Method And Apparatus for Body Impact Protection

ABSTRACT

A motion analysis system includes: at least one orientation sensor configured to detect three-dimensional torso motion over time, the at least one orientation sensor including: a multiaxial accelerometer configured to detect acceleration in at least three orthogonal directions, and a gyroscope; and a controller configured to receive data from the at least one orientation sensor, the controller programmed to process the data to: determine at least one of a state and a transition of the torso; identify normal parameters for the determined at least one of the state and transition; and determine whether motion of the torso is outside the normal parameters. The controller is configured to identify, in real-time, the occurrence of a fall in progress of an individual from at least one of a standing state, a standing-to-seated transition, and a seated-to-standing transition.

This application is a continuation-in-part of U.S. application Ser. No.11/640,783 filed Dec. 18, 2006, which is a continuation-in-part of U.S.application Ser. No. 10/871,238 filed Jun. 18, 2004 now U.S. Pat. No.7,150,048, which is a continuation-in-part of U.S. application Ser. No.10/741,639 filed Dec. 18, 2003 now U.S. Pat. No. 7,017,195, which inturn claims priority benefit under 35 USC §119(e) from U.S. ProvisionalApplication 60/434,732 filed Dec. 18, 2002.

FIELD OF THE INVENTIONS

The inventions described below relate to devices and methods forprotecting the body from injuries that result from impacts and falls,especially in elderly persons via the use of devices to detect a fall inprogress and deploy protective measures.

BACKGROUND OF THE INVENTIONS

Two of the common effects of aging are the onset of osteoporosis orother degenerative bone disease and the impairment of balance so thatfalls are frequent and often the cause of serious injuries in theelderly. In particular, fracture of the hip and pelvis are extremelycommon in older people. Such fractures can occur when a stationary orwalking person falls when standing or sitting, if a person falls out ofbed, or if a person falls down steps. Additionally, serious impacts mayoccur if a person is involved in a vehicular accident where velocitiesare considerably higher.

Persons who experience a hip or pelvic fracture often requirehip-nailing or replacement surgery. While such repairs are often quitesatisfactory, they are expensive and cause a significant financial drainon the health care system. In addition, patients who experience a hipfracture often experience compromised physiological function as a resultof the fracture. In some cases, a patient may die as a result of the hipfracture and its sequelae. Among survivors, a fracture to the hip mayalso start a downward spiral in health that ultimately may lead to lossof independence and necessitating admission to a nursing home. Althoughfracture of the hip or pelvis is an injury characteristic and common tofalling, many other injuries, especially of the brain, cervical spine,arms, and ribs are also common. Falls are, thus, a major cause ofmortality and morbidity.

There are no satisfactory devices available today to protect personsfrom falls or other impacts in such a way that bone fracture may beprevented during every day activities. While people might wear bodyarmor, helmets and the like, such armor and helmets would be too heavy,bulky, unattractive, and cumbersome for people to be willing to wear ona regular basis.

New devices, systems, and methods are needed to recognize when anindividual is falling in order to protect them from the fall or otherimpacts that might lead to bone fracture and other serious injuries.Such devices are particularly important in the elderly where bonestructure and balance may be compromised.

SUMMARY

This invention relates to active devices, fall-sensors and personalairbags used in garments and clothing designed to protect an individualfrom an impact injury, especially those due to accidental falls.

The invention is an active protective system or active protectiongarment (APG) that includes detection, activation, and protectionmechanisms. The protection mechanism is automatically deployed via anair bag inflator when sensors detect the accelerations, directions orrotations associated with the early phases of an accidental fall. Theactive protection system comprises a garment that is worn by a person oranimal requiring protection. The garment may be, depending on the partof the body to be protected, a vest, coat, hat, helmet, pants, shorts,underpants, shirt, undershirt, jumpsuit, shoes, socks, scarf, or otherclothing. The system or garment may further comprise elements added toconventional articles of clothing. The garment, or added elements,comprises structures, analogous to an airbag, that are capable ofinflating or expanding to provide protection to the wearer. The garment,or added elements, further includes sensors, or a plurality of sensors,that detect the orientation of the body or torso, the acceleration, thevelocity, the rotation and the position of the garment or person or theforces acting on the garment itself. The APG further comprises a logiccontroller that is capable of activating the air bag inflator shouldcertain criteria be met or fall outside of an acceptable range. Thelogic controller is capable of distinguishing from a fall another normaldaily activities that can be mistakenly interpreted as a fall. The APGlogic controller interprets electromagnetic inputs from the linkedgyroscopic, position, velocity, or accelerometer devices. The air baginflator is activated by the logic controller, deploying airbags orpockets on or in the garment that are rapidly and automatically expandedto provide energy dissipative or distributive padding to those areas ofthe body, of the person or animal wearing the garment, requiringprotection from the fall or other impact. The garment further comprisesan exterior surface that is capable of withstanding the local forcesthat might be experienced by the garment, including tension,compression, shear, abrasion, puncture, and the like.

The active protection garment for an elderly person, can be a pair ofshorts, or briefs, that are worn about the waist and extend downward tocover and provide active protection for the hips. The APG components canbe built into baffles in the underwear or outerwear. These Upshots canbe underwear or undershirts so that a more stylish garment may be wornovertop of the functional underwear. The Upshots may comprise part of agarment that is worn as the outer layer of clothing. The Upshots mayhave an elastic waistband that is easy to take on and take off. The legopenings may be close fitting, again for ease of the user. The Upshotscan be fabricated from two separate fabric layers of non-gas-porousmaterial, such as, but not limited to, rip-stop nylon, polyester,Kevlar, polyolefin, ePTFE, and the like. The separate layers can befurther subdivided into pockets or chambers that are isolated from eachother. The fabric layers of the APG comprise regions of porosity toallow for breathability.

When the sensors detect the conditions of a fall in progress asevidenced by acceleration, distance, velocity, direction,discoordination, or a combination of parameters, etc., the controllersends a signal, by hardwire or electromagnetic radiation (e.g. radiowaves, infra-red, microwave, etc.), to the logic controller. The logiccontroller sends an electrical or electromagnetic signal to the airbaginflator letting CO₂ (or other) gas move from the canister through theconduits to the subdivided chambers of the APG shorts. Alternatively,the logic controller may send the electromagnetic signal to the valve,causing it to open. The subdivided chambers or airbags inflate to apre-specified pressure. The pressurized chambers provide additionalpadding around the hips to prevent bone fracture when the individualhits the ground or other surface. The multiple isolated chambers preventunwanted redistribution of the pressure away from the impact site on theAPG shorts. The APG is tailored to the anatomy of the site requiringprotection. The garment may also be tailored to accept airbag elementsplaced in pockets designed for this purpose.

The biomechanics or ballistics of falling from standing height requiresthat the system react to deploy within 0.5 seconds or less. For example,in a directly vertical fall from standing, for a 5-foot tall person, thehips drop 2.5 feet, at the 32-ft/sec² acceleration due to gravity,before they hit ground in approximately 0.28 seconds. Other types offalls, including slips while walking, tripping, falling forward, orfalling backward, may involve changes in verticality from the loss ofbalance to the impact. If the sensors detect an orientation, distance,acceleration, or direction that moves beyond programmed limits fromvertical to horizontal too quickly or where the gravitational force onthe sensors falls below programmed limits, the APG shorts are activated.Activation involves deployment or inflation of the airbags. Activation,deployment of the airbag or other barrier, must be complete within afraction of a second from the start time of the fall. The wearer mightnot want to wear the APG shorts on a roller coaster or other ride wheresuch forces might occur and cause a false positive activation.Alternatively, a manual disarm switch may be provided for use incircumstances where the APG might deploy inappropriately orunnecessarily.

The invention also relates to a motion analysis system that can detectnormal motions associated with various different human activities. Theactivities can include the normal acts of walking, sitting and lyingdown, which can be distinguished from falls. Specifically, normalactivities of an elderly person can be distinguished from falls in orderto help prevent injury.

The system includes sensors mounted on an individual's torso. Apreprogrammed logic circuit determines the orientation of the torso andinterprets the trajectory of observed motions relative to the torsoorientation. Multi-function sensors, mounted on the torso of anindividual, are used to sense the orientation of the torso and determineits motions as a geometric solid in three-dimensional space. Through theuse of novel algorithms and rules, it can be determined if the torso ismoving along trajectories that are, or are not, characteristic ofprogrammed normal activities. The direction of the motions of the torso,rather than just the magnitude of acceleration, is used to distinguishfalls from normal activities.

The system includes a logic controller that is capable of distinguishinga fall from another normal daily activities that can be mistakenlyinterpreted as a fall. The logic controller interprets electromagneticinputs from the linked sensors, gyroscopic, position, velocity, oraccelerometer devices.

The algorithm for detection of an accidental fall could use any numberof parameters to trigger inflation of the APG such as: 1) A rotationrate between sensors on the waistband or torso and at the bottom of theleg exceeding 45 degrees in 0.1 seconds would trigger activation of theinflation mechanism; 2) a nearly weightless condition for a period of0.1 seconds would also trigger an inflation; or 3) lateral and verticalaccelerations meeting certain parameters with respect to each other andwith respect to normal values would trigger the inflation. Additionalalgorithms include velocity measurements where the vertical velocity isbecoming increasingly negative (increasingly fast approaching theground) and the horizontal velocity is increasingly positive. Thisscenario correlated with a vertical velocity in magnitude greater thannegative 1 meter per second are strong indicators of a fall in progressand are distinguished from normal conditions such as sitting down,getting into a bathtub, putting on shoes, walking, etc. Another approachis to trigger the device based on velocity slope reversal such as whenthe vertical velocity falls outside a set range such as 1 meter persecond and moves from positive to negative in a short period of time(usually less than 0.25 seconds).

Alternatively, a distance sensor using, for example ultrasound,microwave, radar, sonar, or infrared distance measurement wouldcontinuously ping the environment to determine the distance to objectssuch as the floor, a chair, etc. Derivatives of the distance,specifically by differentiating over time, would be continuouslycalculated to determine velocities and derivatives of the velocity woulddetermine accelerations. Such distance sensors with their first orderand time-differentiated measurements are used to calculate the presenceof a fall in progress. Basic accelerometers can provide much of theneeded information. Here, the nearly weightless condition would be, forexample, an acceleration of less than ½ G, or 16 ft/sec². The inflationperiod occurs in 0.1 second or less. A lateral acceleration exceeding0.5 g for a specific period of time would also trigger deployment oractivation. The distance measuring system operates in conjunction withone or more accelerometers and can provide information relating to theoccurrence of an actual fall in progress.

The relative position of the accelerometer devices may be tracked by thesystem. This can be achieved by keeping a record of location over timeusing a look-back algorithm. However stacking errors will render such asystem difficult to accomplish. One possible method or system is toperiodically re-calibrate position relative to an absolute location,position, or level plane. The plane is preferably defined in theright-left direction, anterior-posterior direction north-southdirection, and up-down direction. The re-calibration is significant todetermine, for example when a wearer is standing up versus lying down orwhen a wearer is standing versus falling.

The sensors may comprise a plurality of accelerometers coupled to aplurality of primary position sensors. The accelerometers and positionsensors are distributed over the person to be protected. One or more orall of these devices can be implantable but could also be made part of agarment or jewelry. Using transponder technology or RFreceiver-transmitter technology, sensors without power supplies may bedistributed around the patient. Energy is transmitted from a powersource to transponders that are distributed at pre-determined locationson the body. The power is used to operate accelerometers and positionsensors in sensor modules. The system can comprise a level that isaffixed, removably or permanently, to the patient. The transpondersperiodically update their relative positions relative to each other andrelative to level as determined by a leveling system. An externalleveling system, on a walker, bed, or chair for example is suitable forproviding the reference points needed to calibrate the system.

The APG can utilize a plurality of accelerometers to determine thestatus of the wearer. An example of an accelerometer suitable for suchpurpose is disclosed in U.S. Pat. No. 5,345,824 to Sherman et al, theentire specification of which is incorporated herein by reference. Theaccelerometers should function in at least two orthogonal planes and atleast two, and preferably three or more, such multidirectionalaccelerometers are used providing three orthogonal directions ofacceleration detection and analysis. Each accelerometer measures alongthree orthogonal axes. Thus, velocity, distance, and acceleration aremeasured along with rotation rates, distances, and accelerations.Outputs from the accelerometers are monitored and algorithms includingintegration and differentiation, are performed to determine velocity anddistance. Velocities in both the forward and negative direction aredetermined by calculating the integral of the acceleration data overtime and position information is obtainable by further taking theintegral of the velocity data over time. Accelerometers such as thosemanufactured by ST Microelectronics, Analog Devices, or Motorola areappropriate for this application. An accelerometer with a range of ±2 gis acceptable for this application. An accelerometer with a range of ±1g is also acceptable and accelerometers with larger ranges might alsowork although they would have reduced resolution in the critical ±1 grange where most fall data occurs. A two-direction accelerometer isadvantageous over a one-direction accelerometer and a three-directionaccelerometer is most advantageous. Two such multi-directionaccelerometers can be used and their outputs correlated to determine theevent of a fall in progress.

The logic circuitry or computer onboard the APG will necessarily run asophisticated program to continuously monitor sensor outputs, integrateor differentiate as necessary, and develop motion information. Thesystem needs to integrate or differentiate the data, continuously trackmotion, and use a look-back function for periods on the order of 1second to 10 minutes. The look-back function should last between 10seconds and 60 seconds. During the look back period, the computer willevaluate motion and determine whether a fall is in progress as dictatedby pre-set conditions or string of conditions or rules. The measuredmotions are continuously evaluated against the rules to determinewhether or not a fall is in progress. Significant computational powerincluding processor speeds and memory are required for such computationsto be performed. For example, a 100 mHz or higher clock speed in theprocessor and memory of 128 megabyte or more is preferred. Sensing ratesof 1,000 measurements per second for three accelerometers along threeaxes implies 9,000 measurements per second. Sixty seconds of data willrequire 60 times 9,000 or 540,000 measurements. The memory will requireapproximately 1 megabyte to hold 540,000 16-bit words. To obtainvelocity and distance, another 2 megabyte of 16 bit words are required.Computational storage may require an additional 32 megabytes of memory.Therefore a system with approximately 48 to 64 megabytes of memoryshould be more than sufficient.

Alternatively, the sensor outputs can be recalibrated at predeterminedintervals based on the user activity or position of the body, withoutany reference to any external standard. New programs can triggeredwithin the logic circuit based upon the state of the monitored user oron the observation by the logic controller of a transition betweenpredetermined states. Parameters can be programmed for allowable motionsin each direction for each predetermined body-state and transition.

The logic circuitry can be programmed with algorithm rules that definethe motion signatures for the major activity states as well as thetransition between the states. Additionally, other rules define thesignificant departures from the normal motions that indicate falls orthe harbingers of falls. The three normal human activity states aredefined as the state of standing or walking, the state of being seatedand the state of recumbency. The normal transition states are: 1) fromthe standing state to the seated state; 2) from the seated state to thestanding state; 3) from the seated state to the recumbent state; and 4)from the recumbent state to the seated state. The recognition of thesetransition sequences establishes the body-states for use by the logiccontroller. The logic controller is programmed to recognize the patternsof normal translations between states and how these differ from fallmotions. The individual state and transition programs will recognizenormal and abnormal patterns of motion for the state or the transition.The program for each state is triggered either by the end of thetransition to that state or by the observation of signature motion forthat state. The transitional programs are triggered by the observationof signature torso motions that indicate the possibility of a transitionbetween one state and another. Observed torso motions will be referencedto the body state or transition as being normal or abnormal. Parametersare programmed for allowable motions in each direction for eachbody-state and transition. This is performed by either a neutral networkor a statistical program of pattern matching. The range of normaltrajectories during each of the transitions is established. Downwardmotions of the torso not corresponding to programmed parameters for agiven transition because of abnormal sequence, acceleration ortrajectory is recognized as falls. The delineation of the normal motionsignatures for the standing/walking state, the seated state and therecumbent state and for the transitions between states is programmedduring a training phase.

Alternatively, in the APG system, sensors can be located in or on thepatient. The sensors are transponders or RF ID type devices. Atransmitter transmits wireless signals at a certain frequency. The RF IDtransponder receives the information and re-transmits at a newfrequency. A sensor or sensors mounted on the patient determine the beatfrequency between the transmitting and receiving transducers andcalculates relative motion between the two transducers using Dopplershift methodology. This method can be used to determine the distancebetween a plurality of transducers affixed, removably or permanently, tothe patient. The RF ID device, can also use microwave, RF, ultrasound,sound, or simple electrical signals transmittable through body tissue,and the like.

The APG system comprises algorithms to understand whether the person iswalking, standing, sitting, lying down, or the like. These algorithmsare used to supplement and real-time and/or look-back motion data todetermine whether a fall-in-progress is occurring.

The APG can comprise rotational acceleration sensors such as the typemanufactured by ST Microelectronics. Such rotational accelerationsensors are capable of measuring rotational acceleration. Theinformation can be derived over time to obtain rotational velocity andderived again over time to obtain rotation distance or angle. Suchrotational acceleration information can be used alone or in conjunctionwith other accelerometers or distance sensors to detect a fall inprogress. A rotational accelerometer system has the potential toeliminate the need for one or more linear accelerometers in the entiresystem, thus providing for more simplicity and cost-savings.

The APG can also comprise one or more gyroscopes of the type disclosedin U.S. Pat. No. 6,470,748 to Geen, the entire specification of which isincorporated herein by reference. The gyroscopes can be used alone, orin conjunction with the accelerometers.

A plurality of accelerometers or other sensors can be distributed on thepatient by either implantation, or by adhesive attachment to the patientvia a patch or patches. The implantation or adhesive attachment to thepatient provides reliable, repeatable location for the sensors that canbe relied on to generate data that is useable by the logic controller todetect a fall in progress. Sensors that are not well affixed to thepatient, such as those affixed to garments or jewelry, will be less wellattached to the patient so positioning is less accurate and more subjectto errors in measurement or inappropriate locating by the patient. Thelogic circuitry generally requires exacting knowledge of the positioningof the sensors to determine the interrelationship between themeasurements that are taken. The logic circuitry integrates ordifferentiates the data from the plurality of sensors, preferably threeor more three-dimensional sensors that can measure motion in threedirections and three axes of rotation, relative to time. Rotation ratesof accelerometers requires that acceleration data be derived todetermine velocity and that the moment arm between the two sensors beknown with substantial precision.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A illustrates a pair of deflated APG shorts;

FIG. 1B illustrates a cross-sectional view of one of the deflatedchambers of the APG shorts;

FIG. 2A illustrates a pair of APG shorts following activation;

FIG. 2B illustrates a cross-sectional view of a chamber of the APGshorts following activation;

FIG. 3A illustrates a block diagram of the components of a pair of theAPG shorts;

FIG. 3B illustrates another block diagram of the components of a pair ofthe APG shorts with actuator valves;

FIG. 4 illustrates a front view of a pair of APG shorts being worn by anindividual;

FIG. 5A illustrates a side view of a pair of APG shorts on a standingindividual;

FIG. 5B illustrates a pair of APG shorts, which have activated becausethey are being worn by an individual who has begun falling;

FIG. 5C illustrates a pair of APG shorts being worn by an individual whohas fallen and whose hip has struck the ground;

FIG. 6 illustrates a pair of APG shorts with distributed activationmechanisms;

FIG. 7A illustrates an APG collar on a jacket prior to activation;

FIG. 7B illustrates an APG collar on a jacket following activation;

FIG. 8A illustrates an APG jacket prior to activation, according toaspects of an embodiment of the invention;

FIG. 8B illustrates an APG jacket after activation;

FIG. 9A illustrates a pair of APG trousers prior to activation;

FIG. 9B illustrates a pair of APG trousers following activation; and

FIG. 10 illustrates a rear view of a pair of APG shorts with pocketsinto which APG components are inserted.

FIG. 11A illustrates a rear view of a person wearing a harness;

FIG. 11B illustrates a front view of a person wearing a harness;

FIG. 11C illustrates a front view of the harness without the wearer; and

FIG. 12 illustrates a person with a series of deployed anatomicallyshaped airbags

DETAILED DESCRIPTION OF THE INVENTIONS

FIG. 1A illustrates pair of deflated APG shorts 10. The APG shorts 10comprise a plurality of chambers 12, a plurality of accelerometers 14,one or more optional gyroscope 16, a high pressure or compressed sourceof gas 18, a logic controller 22, a battery 24, an electrical bus 26, amanifold 28, a plurality of chamber inlet ports 30, and a plurality ofone-way valves 32. The APG shorts can optionally have an actuator valve20. The chambers 12 can further comprise two layers of gas impermeablewall 34 and 36, a plurality of seals 38 and one or more non-inflatableregions 46.

The chambers 12 are isolated regions within the APG shorts 10 thatcushion the impact between the wearer and the object being hit by thewearer. The chambers 12 are connected to the high pressure or compressedgas source 18 by a manifold 28. A valve 20 may be contained to controland enable the gas flow from the compressed gas source 18 to themanifold 28. The entry to each chamber 12 is a chamber inlet port 30.Each chamber inlet port 30 may be connected to the manifold 28 by aone-way valve 32. The valve 20 is opened or closed by the logiccontroller 22, which is further powered by a power supply 24. Inputs tothe logic controller 22 are electrically connected to a plurality ofaccelerometers 14 and/or a plurality of gyroscopes 16 by an electricalbus 26. The APG short also comprise a plurality of non-inflatableregions 46. All components are affixed to the APG shorts 10.

The chambers 12 can comprise cornstarch, talc or other dry lubricant toprevent blocking or wall adherence that could prevent proper inflationwhen desired.

The high pressure or compressed gas source 18 can be a canister of gassuch as, but not limited to, carbon dioxide, nitrous oxide, nitrogen,argon, or the like. The high pressure or compressed gas source 18 mayalso be a pyrotechnic device or a catalytic device that, once activatedby the air bag inflator, generates a gas such as nitrogen, carbondioxide or other non-flammable material, that expands under greatpressure to fill the manifold 28 and the chambers 12. A typicalsolid-state gas source comprises sodium azide (NaN₃) with a potassiumnitrate (KNO₃) oxidizer encapsulated within a filter and containmentchamber with holes through which gas can escape. The device furthercomprises an electrical air bag inflator that causes activation when theproper electrical signal is applied to the inflator. Typical devices ofthis type use 12 Volts DC and 750 milliamps to activate the inflatoralthough lower energy inflators are possible and desirable. Such gassources 18 are capable of fully outgassing beginning around 5milliseconds from the presence of the electrical signal in the inflatorand completely outgassing in times as short as 40 milliseconds or less.Longer outgassing times, up to 100 or 200 milliseconds, may beappropriate for the application of the Active Protective Garment. Veryfast outgassing devices have uses in systems where the fall is detectedin its terminal stages or even after impact when a velocity reversaloccurs. Extremely fast inflation at that point may still distributeforces and prevent injury to the wearer.

When the Active Protective Garment contains a valve, 20 the valve isactivated either by motor or explosively operated such that once atriggering signal is received from the logic controller 22, the valveopens within less than 0.05 seconds and preferably within less than 0.01seconds. The high-speed opening mechanism of the valve 20 is eitherfusible or motor-driven. The valve 20 optionally comprises a pressureregulator to ensure that the proper pressure is applied to the manifold28 and, subsequently, the chambers 12. When the valve is not present,the air bag inflator deploys within these same time limits.

The one-way valves 32 are passive valves that permit gas to enter thechamber inlet ports 30 but not to escape in a retrograde direction.Valves of this type include, but are not limited to, duck bill valves.

One or more non-inflatable regions 46 are located in areas that normallywould not require protection and which, if explosively inflated mightcause damage or discomfort to the person wearing the APG shorts 10. Suchareas where a non-inflatable region 46 is appropriate include the crotcharea. Selective areas of non-activation such as the non-inflatableregion 46 are preferably in areas that would not normally receive animpact load during a fall.

The electrical bus 26 includes all electrical wiring between thesensors, including the gyroscopes 16 and the accelerometers 14 and thelogic controller 22. The electrical bus 26 is also comprised within thelogic controller 22 interconnecting all components electrically. Theelectrical bus 26 also connects the logic controller 22 and the air baginflator or the valve 20, thus sending a signal to open at theappropriate time.

FIG. 1B illustrates a cross-sectional view of a chamber 12 of thedeflated APG shorts 10. The chamber 12 further comprises an inner wall34 and an outer wall 36, seals 38, and an interior volume or space 42.Suitable materials for the inner wall 34 and the outer wall 36 include,but are not limited to, polyester (PET), polyimide, polyurethane,polytetrafluoroethylene (PTFE), nylon, Dacron, Kevlar, copolymers of theaforementioned, rip-stop nylon, cotton, and the like. The inner wall 34and the outer wall 36 may be of different materials or they may be ofthe same materials. The material is preferably woven to maximizestrength although knitting or other fabric forming processes are alsoacceptable. Strengthening fibers fabricated from Kevlar or polyester,for example, may be used in conjunction with weaker materials to form abarrier cloth that is impermeable to gas but also has reinforcingstrands. Impermeability may be achieved by coating a woven or knittedfabric with membranous materials such as polyurethane or PTFE.Alternatively, the entire wall 34 and 36 can be fabricated frompolymeric sheet that is not woven or reinforced but is homogeneous.

FIG. 2A illustrates a pair of APG shorts 10 following activation.Referring to FIGS. 2A and 1B, the plurality of chambers 12 have becomefilled with pressurized gas and bulge outward to form a paddedstructure. Any amount of pressure generated within the interior volume42 of the chambers 12 will provide some protection for the wearer,although sufficient pressure to prevent collapse of the exterior wall 36against the interior wall 34 is preferable. For example, a 200-poundperson resting on a 12-inch by 12-inch area or 1-foot square wouldrequire 1.39-pounds per square inch (PSI) internal pressure to supportthe weight. The same two hundred pound person falling from 2.5 feetwould have an impact velocity of 8-ft/sec and exert a force greater than200-lb due to their momentum. If they decelerated to a stop in 0.05seconds when they hit the ground, the net force would equal 1000 pounds.Thus, the APG shorts require at least 6.94-pounds per square inch (PSI)to cushion the fall over a 1-square foot (144 square inch) area, underthis scenario.

FIG. 2B illustrates a cross-sectional view of a chamber 12 of the APGshorts 10 following activation. The chamber 12 further comprises theinner layer 34 and the outer layer 36, a plurality of seals 38 and aninner volume 42. The chamber 12 has become inflated with pressurized gasand forms a padded structure to protect the wearer. The internalpressure within the internal volume 42 of the chamber 12 is sufficientto prevent collapse of the inner volume 42 between the inner layer 34and the outer layer 36 of the chamber 12. The width of the seals 38 issufficient to provide a strong bond so that the two layers 34 and 36 donot become separated by the tensile forces created by the pressurizedinternal volume 42. The width of the seals 38 is not so wide that theperson wearing the APG shorts 10 would be unprotected if they fell onthe seal 38. The seal 38 can be a heat seal created by compression ofthe two fabric layers 34 and 36 at specified temperatures, pressures andtimes such as to form a strong weld between the two layers 34 and 36 ofmaterial. Alternatively, each chamber 12 can be separate from the nextand the separation wall does not comprise a seal 38.

FIG. 3A illustrates a block diagram of the systems comprising the APGshorts. The APG shorts comprise a plurality of cushioning chambers 12,one or more accelerometers 14, one or more gyroscopes 16, a highpressure or compressed gas source 18, a logic controller 22, and a powersupply 24.

The logic controller 22 is a computer and controls all aspects offunction of the device from acquiring information from the gyroscopes 16and the accelerometers 14 to determining whether an actuation conditionexists to the airbag inflator (not shown) to inflate the chambers 12 toproviding notification of the status of the power supply 24 orcontroller 22 malfunction. The software (not shown) controls thefunction of the logic controller 22.

The power supply 24 can be a battery system powered by chemistries suchas, but not limited to, lithium ion, nickel metal hydride, nickelcadmium, alkaline, lead-acid, and the like. The power supply 24 provideselectrical power at the correct voltage and current to the electricalcomponents of the APG shorts 10. The power supply 24, optionally furthercomprises a connection to either 110 VAC or 240 VAC power and serves asa charger for the battery, if appropriate.

The accelerometers 14 can be strain gauge devices that suspend a weighton one or more strain gauges. The strain gauges operate within aWheatstone bridge signal conditioning circuit to cause voltage orcurrent changes in the circuit proportional to the stress on theaccelerometer 14. Strains and stresses in multiple directions may bemeasured using a plurality of these strain gauges. The strain gauge,signal conditioners, amplifiers and other required components may becomprised within a single monolithic structure for manufacturability,small size, low cost, and reliability. The accelerometers 14 may bedistance or position sensors such as those employing ultrasonic acousticwaves, radar, microwave, infrared, or other methods to determinedistance between the sensor and the ground or other object.Differentiation of the signal provides velocity information and furtherdifferentiation provides acceleration information. The velocity,distance, and acceleration information can be correlated to signal afall in progress and activate the APG shorts 10.

The accelerometer 14 can be an ST Microelectronics LIS3L02. This deviceis available as either an analog or digital output device capable ofmeasuring acceleration along three orthogonal axes. It is amicro-electromechanical system (MEMS) based chip that requires supportcircuitry including power supply, timing, and output circuitry.

The gyroscope 16 may be a ball or sphere suspended concentrically withina sphere. The outer sphere is affixed permanently to the APG shorts 10.The inner sphere is magnetically suspended within the outer sphere. Theinner sphere is weighted so that slow motions of the outer sphere movethe inner sphere in a 1:1 ratio. Fast motions of the outer sphere exceedthe magnetic attraction between the two spheres and the inner sphererotationally displaces relative to the outer sphere. Such rotationaldisplacement is detected by changes in the magnetic field, electricfield directed toward a portion of the inner sphere, etc. Rotationaldisplacements sufficient to announce a fall in progress causes the logiccontroller 22 to send an opening command to the airbag inflator.Standard gyroscopes using spinning tops or other stabilization systemsare acceptable for this use but require higher power drain and are moreprone to reliability problems.

The gyroscope 16 can be replaced by one or more rotationalaccelerometers. Each rotational accelerometer can measure rotationalacceleration about three axes, X, Y and Z. The rotational accelerometer,such as the one manufactured by ST Microelectronics is capable ofproviding rotational acceleration information. Taking the integral ofthe acceleration over time results in the rotational velocity. Asingle-axis rotational accelerometer is the ST MicroelectronicsMEMS-based LIS1R02, an analog output accelerometer capable of performingthe tasks required for this application. Support circuitry includingmemory, Analog to Digital conversion, clock, power, and the like arerequired for such a device. Integrating the rotational velocity datawill yield rotational displacement, angle, or distance.

FIG. 3B illustrates another block diagram of the components of a pair ofthe APG shorts with actuator valves. The APG shorts comprise a pluralityof cushioning chambers 12, one or more accelerometers 14, one or moregyroscopes 16, a high pressured or compressed gas source 18, an actuablegas valve 20, a logic controller 22, a power supply 24, an electricalbus 26, a gas manifold 28, a plurality of chamber ports 30, and aplurality of one-way valves 32.

The logic controller 22 is a computer and controls all aspects offunction of the device from acquiring information from the gyroscopes 16and the accelerometers 14 to determining whether an actuation conditionexists to activating the valve 20 to inflate the chambers 12 toproviding notification of the status of the power supply 24 orcontroller 22 malfunction. The software (not shown) controls thefunction of the logic controller 22.

The software can be programmed to perform according to predeterminedconditions set by the certain parameters. The state of the body asstanding, seated or recumbent, can be recognized by a combination of 1)the motions intrinsic to the state; 2) the orientation of torso sensors;and 3) the transitions that lead to the state. The software can bepreprogrammed to have a specific program for each state and eachpotential transition. The individual state and transition programs willrecognize normal and abnormal patterns of motion for the state ortransition. The program for each state will be triggered either by theend of the transition to that state or the observation of signaturemotion for the state. The transitional programs will be triggered by theobservation of signature torso motions that indicate the possibility ofa transition between one state and another. New logic programs can betriggered within the logic controller based upon the state of thepatient or on the observation of a transition between states. Thesensors can be recalibrated based on the activity or position of thepatient's body, and without reference to any external standard. Therange of normal trajectories during each of the transitions ispreprogrammed into the logic controller. Downward motions of the torsothat do not correspond to the preprogrammed parameters for a giventransition due to an abnormal sequence, acceleration of trajectory arerecognized as falls. The delineation of the predetermined range ofnormal signature motions for each state can be programmed during atraining phase.

The logic controller can be programmed to use threshold accelerations todetect an actual fall and eliminate false positives. The thresholdaccelerations can also be combined with vertical displacement to createan additional program where the deployment thresholds for accelerationsand for estimated vertical displacements are used together. Deploymentcan be indicated by accelerations above thresholds that varyappropriately with the orientation of the patient's torso. The thresholdaccelerations can utilize vertical and lateral accelerations either as atotal acceleration relative to gravity, total acceleration includinggravity, or as separate thresholds on either vertical or lateralaccelerations.

The preprogrammed phases are the standing state (S1), the seated state(S2) and the recumbent state (S3). The standing state (S1) is recognizedif the sensors are in a vertical alignment, a walking signature motionis observed and there is no transition or fall. The standing state isalso recognized to exist if a seated state to standing transition hasbeen observed and no fall has occurred during the transition. Patientsreach the seated state (S2) by transition from either S1 or from S3. Aperson will be considered to be in S2, triggering the program for thisstate if the torso is within 45 degrees of vertical and if an S1 to S2transition has been observed without a fall or a further transition torecumbency. A person who is in the seated state and who shows notransition to standing or to recumbency will be considered to beremaining in S2. A person will also be regarded in the seated state if atransition from S3 to S2 has been observed. It is characteristic of theseated state that the pelvis will be vertically stable although theupper torso tilts over a broad range. A person will be recognized asbeing in the recumbent state if the torso orientation is within about 20degrees of horizontal, if the transition from S2 to S3 has been observedand there is no fall. Rotation around the axis of the torso without muchchange in the magnetometer orientation of the axis is common in therecumbent state.

The logic controller often cannot determine if an observed motion isnormal based entirely on the motion signature itself. Before it caninterpret the normalcy of a motion, the logic controller must know thecontext (body state) in which the motion is occurring. The programmedrules by which it judges normal and fall motions will specify the statethat the torso was in at the onset of the potentially significantmotion. In addition to the recognition of three normal states, thetransitions are also recognizable from torso motion. The normaltransitions are 1) from the standing state to the seated state; 2) fromthe seated state to the standing state; 3) from the seated state to therecumbent state; and 4) from the recumbent state to the seated state.The recognition of these transition sequences helps to establish thebody states for use of the logic controller. Moreover, because falls canoccur during transitions, the logic controller recognizes the pattern ofnormal transitions between the states and how these differ from fallmotions. The individual state and transition programs can recognizenormal and abnormal patterns of motion for the state or transition. Theprogram for each state will be triggered either by the end of thetransition to that state or by the observation of signature motion forthe state.

The transitional programs will be triggered by the observation ofsignature torso motions that indicate the possibility of a transitionbetween one state and another. The logic controller can be recalibratedbased on observed user activity of the body. Sensors can be placed onthe user's body in order to program normal and transition states thatare unique to the user. For example, where the height of the sensorsabove the ground when the user is standing are known, the sensors wouldrecognize when the user is walking or standing. If the user is observedgoing from a standing state to a seated state, that is, if the user wentthrough the transition for assuming the seated position, the approximateheight of the sensors could also be inferred once the user has completedthe transition and is in the seated state. This is also true for therecumbent position. New programs may be triggered within the logiccontroller based upon the state of the monitored user or on theobservation of a transition between states. Observed torso motions willbe referenced to the body state or transition as being normal orabnormal. Parameters will be programmed for allowable motions in eachdirection for each body-state and transition. The normal range oftrajectories during each of the transitions will be established.Downward motions of the torso not corresponding to programmed parametersfor a given transition because of an abnormal sequence, acceleration ortrajectory will be recognized as falls. The delineation of the normalmotion signatures for the standing/walking state, the seated state andthe recumbent state for the transition between states are programmedduring a training phase.

The fall recognition for the S1 state includes several rules. First,forward, right anterior torso tilting of up to 90 degrees that is notaccompanied by axial acceleration beyond a programmed limit ispermitted, within 30 to 45 degrees on either side of the directanteroposterior axis. Such tilting may signal either a reach or thebeginning of a transition from the standing state to the sitting state.This rule can be modified by acceleration and trajectory parametersduring training. Second, posterolateral, or lateral tilting of the torsomore than 30 to 45 degrees on either side of the directedanteroposterior line, accompanied by any pelvic/torso descent is definedas a fall. Any posterior or postcerolateral descent of greater that 10inches is defined as a fall unless the prior transition program forstanding state to sitting state has been activated. Third, Cephalad,axial acceleration of the torso beyond programmed limits, or accompaniedby a downward motion is defined as a fall. Fourth, Kyphosis, the use ofa cane or a walker may set, as normal, a slight unilateral tilt.Observation of these variations during the training phase will allow theuser's customary posture to be programmed as well as the normal verticalposture. Fifth, to accommodate elevator travel, direct vertical ascentand descent will be accepted as a normal motion for a person in thestanding state. Sixth, the motion of walking will be recognized bycharacteristic, low amplitude, vertical undulations and forward motion.Because the length of stride in most elderly individuals is fixed, thefrequency of the undulations will serve as an indicator of the rate ofanterior motion.

The parameters for S2 permit torso motions that are categoricallyabnormal in S1. The program for S2 will allow for a wide range of torsotilting in the posterior or lateral directions, down to 90 degrees ormore, because such motions are associated with the normal transitionfrom the seated state to the recumbent state. Anterior torso tilting inthe seated state is also tolerated up to 90 degrees, as long as thepelvis does not descend and the vertical orientation of the torso is notreversed. These parameters can be modified by observation made duringthe training phase. However, the program for the seated state will allowalmost any motion except a reversal of the vertical orientation of thesensors, excessive axial acceleration in the cephalad direction or theshock of a collision. Motions of wheelchair or automobile travel will beaccepted as normal by the S@ program. Also, direct vertical ascent ordescent, as in an elevator, will also be accepted as normal by the S2program.

The program for the S3 state will recognize the height of the sensors asbeing 24 inches above the ground and any descent of greater than 6inches within 5 seconds of a torso rotation will be recognized as afall. As for all of the state and transitional programs, normalparameters will be established during a training phase.

The transitional programs can recognize stereotypical human motions thatcharacterize the passages between S1, S2 and S3. The recognition by thelogic circuit of motion signatures that indicate a possible transitionwill trigger the activity of the program covering possible transitions.The transition programs vary according to the steady state from whichthe transition originates. Torso motions observed during the possibletransitions will be compared to normal and expected sequences andtrajectory parameters that have been programmed into the logic circuitduring the training phase. Motions that depart by reasons of sequence,acceleration, velocity, distance, rotation or trajectory from the normalparameters may be recognized as falls. Falls can be recognized byabnormal motions during transitions or during steady states. Theaccurate recognition of the onset of a possible transition necessary toinitiate the program for allowable motions during the passage from onestate to another and to distinguish the new state the torso is entering.

Two important principles are involved in distinguishing the S1 to S2transition from a fall. The first is that people generally walk forwardand sit down backward. The second is that controlled transitions betweenS1 and S2 require a sustained anterior tilting of the torso to maintainthe center of gravity over the thighs during a sitting descent. Thus, ananterior tilt of the torso of between 15 and 45 degrees in a standingposition is the necessary, although not sufficient, condition of anormal, potential transition from S1 to S2. It is this motion thatpermits the slow, controlled, posterior descent of the torso over arelatively steep trajectory. It is virtually impossible to pass normallyfrom S1 to S2 without this tilted posture. The degree of the anteriortorso tilt and the trajectory of the posterior descent are both likelyconsistent from one S1-S2 transition to another for an individual, andthey may not vary much between individuals of similar age, size andconditioning. The controlled posterior descent of the pelvis in theS1-S2 transition is slower than the descent of most posterior falls. Thelogic controller is programmed to recognize a possible transition fromS1 to S2 by an anterior tilting motion of the torso greater than 15 to45 degrees, or within a range that has been determined during thetraining mode to be normal for the user. The tilting of the torso beyonda prescribed threshold triggers the transition program for S1-S2. Fallsare distinguished by departures in acceleration or trajectory from thenorms that are programmed. Posterior descent without the expected degreeof anterior torso lift are recognized as falls. The torso tilt requiredby the transition from standing to seated state may be anterior orslightly anterolateral (within 45 degrees of a direct A-P axis). Thetransition program will not recognize lateral or posterolateral tiltingof the torso as S1-S2 transitional movements. Unique sitting techniquesto pass through the transition from S1 to S2 can be programmed duringthe training phase as a normal transition to sitting for the individual.Additionally, the normal sitting motion for users who walk with a caneor a walker can also be recognized during the training phase. However,in every case, a marked anterior tilting of the torso is an essentialcondition for a controlled posterior torso descent and is the signaturemotion to trigger the S1-S2 transition program. The transition fromS1-S2 will be regarded as complete when the following conditions aremet: 1) the pelvis has reached an end of its descent and there is asignature recoil observed; and 2) the anterior tilt of the torso isreversed. Once the transition is completed and the patient is recognizedas being in the S2 state, the S2 program will run until interrupted byanother potential transition or fall.

The seated state allows for two possible transitions. A seated personwill either fulfill the stereotypical transition for assumption of S3 orwill attempt to transition to S1. The anterior tilting motion of thetorso is necessary in the ascending transition from S2 to S1. Therefore,the transition from S2 to S1 requires a signature anterior tilt of thetorso of more than 30 degrees. This motion by a user in S2 signals apossible transition to S1. The transition program is initiated whenthere is an upward and forward acceleration of the forward-tilted torso.Pelvic rotation of 15 to 30 degrees may accompany the attempt to stand.Falls during the S2-S1 transition are recognized by abrupt forwardpitching with cephalad acceleration along the axis of the torso orlateral accelerations outside the expected parameters for the normalmotion of rising from the seated state. The end of the transition fromS2 to S1 is recognized when one of the three conditions is met: 1) theascent stops after a normal trajectory without any intervening fall; 2)when the torso tilt is reversed and the normal vertical state of thetorso is restored; or 3) when the walking motion is observed.

The transition from S2 to S3 is activated when the torso has tilted morethan about 60 degrees laterally or posteriorly from the vertical of theseated state. The torso may move through an eventual arc of 90 degreesfrom vertical, either to the side or to the back. The completion oftransition from S2-S3 is recognized when the upper portion of the torsohas ceased descending and the orientation of the axis of the torso ishorizontal. As the transition to a sitting state is completed or nearscompletion, and possibly before the descent of the torso has stopped, areclining person may tilt sideways or backward to transition to therecumbent state. The transition program recognizes this as normal andtherefore a rule may be programmed that lateral tilting of the torso ispermitted in the last stages of an otherwise normal S1-S2 transition.

The transition from the recumbent state to the sitting state must takeinto account the weakness of the anterior abdominal muscles. In order toreach the state from recumbency, the patient must turn on one side oranother and lift the torso slightly using the arms for support. Next,one or both legs are dropped over the side of the bed and the torso arcsupward to an erect position. The end of the transition from therecumbent to sitting state will be recognized when the upward motionceases and the torso has reached an almost vertical orientation. At thispoint it will be common to see the beginning of the S2-S1 transition.

The crucial transitions from S2 to S1 and S1 to S2 which involve achange in the height of the entire torso, are characterized by aninitial forward tilting of the torso beyond a threshold which triggersthe transitional program. Despite this anterior tilt, anterior anddownward acceleration of the torso is not characteristic of any of thetransitional movements.

Although an anterior tilt of the torso is crucial to the initializationof the possible transition programs between S1 and S2, there are severalinstances in which such anterior tilting could be caused by actionsother than the intended transition from one state to another. Theprogram can anticipate the stereotypical follow-on motions to completethe transition to a different state. However, pseudotransitions mayoccur. Pseudotransitions are distinguished from real standing to sit orsit to stand transitions by the absence of significant pelvic descentfrom S1 or upward pelvic movement from S2 along expected trajectoriesand within a few seconds.

Pseudotransitions are distinguished from falls by the absence ofacceleration along abnormal descending trajectories. Without descent orrise of the torso there can be no transition from one state to theother. Thus, an S1 to S2 transition cannot be occurring if the torsodoes not descend along the trajectory expected for the distance and thetime required in the sitting transition. Similarly, an S2 to S1transition cannot exist if the torso does not rise a distance necessaryto reach the standing state. Therefore, pseudotransitions aredistinguished from real transitions by this means.

The transition programs have a time limit based on the expectation ofeither completion of the change in state or of a fall within a fewseconds of the onset of the anterior torso tilt. Torso tiltunaccompanied by change in the vertical height of the torso arerecognized as a pseudotransition if the transition algorithm is notcompleted within a few seconds after the torso tilt is observed. In thecase of a pseudotransition, the program will revert to the status reset,that is the state in which the user was known to be prior to the torsotilt. The degree of torso tilt in the anterior direction that define apossible transition are determined by observation during the trainingmode.

A separate type of pseudotransition may occur in the S2 to S1 transitionprogram. If a user in the S2 state attempts to stand, that is, tilts thetorso forward and drive the pelvis forward and upward, weakness orataxia may cause the patient to pitch forward or laterally. Thesemotions are recognized by the program as falls during the transition.

In addition to the steady state programs for S1, S2 and S3 and thetransitional programs which recognize the movement between one state andanother, several harbinger motions may also be recognized. Theseharbinger motions have a high probability of leading to a fall andwhich, even absent of falling motion, may deploy protective measures.These harbinger motions consist of: 1) backward walking of more than oneor two steps with or without torso rotation; 2) wobbling or unsteadyanterior-posterior or side-to-side instability of the user in the S1state; 3) sudden impact acceleration or deceleration reflecting acollision with an object or another person; and 4) abnormally rapidwalking with a forward torso tilt. An acceptable rate of walking basedon the number of low amplitude undulations per minute will be programmedinto the S1 program during the training phase so that rapid walkingpatterns can be recognized.

The logic controller is programmed to recognize potential fall relatedmotions in each steady state and transition program. Falls arerecognized as accelerations, trajectories or rotations outside theaccepted parameters for normal activities. Almost all falls arecharacterized by motions that depart from normal trajectory parametersin direction, acceleration, velocity, duration or rotation and by theabsence of preliminary, normal, transition motions. Falls arecharacterized as uncontrolled descents of the center of mass and willtherefore lack the stereotypical postures consistent with controlleddescent. It is this absence of controlling posture with results in theabnormal velocities and directions of descent. Because fall motionscannot themselves be trained into the state and transition programs,they will be defined as significant departures from the normaltrajectories.

When falls arise out of the S1 state or occur during transition from S1to S2 or S2 to S1, most human falls are characterized by one of threeeasily recognizable, categorically abnormal motions. The first of theseabnormal motions is lateral and downward torso acceleration beyond theparameters of normal motion for a person in the S1 state or in an S1 toS2 or S2 to S1 transition. Such fall motions may be directly lateral,anterolateral or posterolateral. They occur along trajectories that arenot observed in the normal S1 or transitional states. The secondcategorically abnormal motion for a person in the S1 state or in atransition is an anterior pitch in which the torso accelerates cephaladalong its axis at a rate not seen in normal states or transitions. Thissort of forward pitching fall may occur during walking or during anattempt to rise from a seated state. The third motion that iscategorically abnormal from the S1 state is a backward and downwardmotion of the torso without the prior transitional movement of a forwardtorso tilt of at least 15 to 30 degrees. Such posterior falls occuralong abnormal trajectories and often at high speed. The upper torso iseither less tilted anteriorly than is necessary for a controlled descentor is actually tilted posteriorly, accelerating the fall motion. Thesefall types from the S1 state may result from tripping and pitchingforward or from staggering and collapsing backward and sideways. Theclassic “heel slip” fall results in a backward or postrolateral anddownward motion of the torso at very high speed.

The transition from S2 to S1 is one of the most common occasions ofinjurious falls in the elderly, commonly occurring at night. As a personattempts to rise from a recumbency to sitting then to standing, he mayfall over anteriorly or laterally. If the predicted S2-S1 sequence isinterrupted by an abrupt, lateral or downward or anterior and downwardacceleration, a fall is recognized. If, on the other hand, thetransition-interrupting acceleration is posterior and downward, to alevel not lower than the original seated state, a pseudotransition willbe recognized. Thus, interruption of the S1-S2 transition either by afall or a pseudotransition can be recognized. This distinction dependson the direction, distance and velocity of the descent. If the userreaches S1, as evidenced by a vertical position of the sensors after thearrest of normal upward movement or the recognition of the walking gait,the S1 program will be activated and any subsequent descent along anabnormal trajectory will be recognized instantly as a fall.

Falls from the S2 state may take the form of a forward pitch, or alateral or posterior fall from a chair or other platform. Such falls canbe detected by the S2 program if there is a reversal of the verticalorientation of the torso or excessive axial acceleration of the tiltedtorso. Falls from the seated state, as opposed to falls arising duringtransitions, are uncommon and usually not dangerous.

Falls from the S3 will involve rotations around the axis of the torsofollowed by descent of part, or all, of the torso. These falls from bedor from a couch are generally low energy and can be detected by passagethrough a threshold distance from the floor. Many un-witnessed fallsthat result in the patient being found on the floor next to his bedactually occur during attempted transitions to S1, not tumbling out ofbed.

A person is recognized in a seated state if the torso is within 45degrees of vertical and if a standing state to seated state transitionhas been observed without a fall or a further transition to recumbency.In a seated state, the pelvis will be vertically stable although theupper torso tilts over a broad range. A person is recognized in astanding state where there is vertical alignment of the sensors after atransition from a seated or recumbent state, a walking signature motionis observed and there is no transition or fall. A person is recognizedin a recumbent state if the torso orientation is within about 20 degreesof horizontal, if the transition from sitting to recumbency has beenobserved and there is no fall. Rotation around the axis of the torsowithout much change in the orientation of the axis is also common in therecumbent state. Falls are recognized as downward motions of the torsothat do not correspond to the preprogrammed parameters for a giventransition due to an abnormal sequence, acceleration or trajectory.

The logic controller can also be programmed for fall detection ofaccidental falls of a rider of a horse, bicycle, motorcycle, or thelike. The sensors may be used to track the attitude, orientation,accelerations and three-dimensional trajectories of the rider and thecycle or horse. The logic controller can be programmed to compare theseattitudes, orientations and trajectories for the purpose of determiningwhether they are normal or abnormal. Movement tending to produce a wideseparation of the lower torso of the rider from the vehicle isconsidered abnormal and indicative of descent from the horse, bicycle ormotorcycle.

The logic controller can be programmed to determine whether anequestrian, bicyclist or motorcyclist is falling or is otherwise indanger because of extreme lateral, forward or backward attitude andacceleration when the rider and vehicle are falling together. Thisdetermination can be made even when the animal or vehicle and rider aregoing through complex patterns of radical acceleration and decelerationin multiple dimensions in order to deploy devices capable of protectingthe rider from injuries caused by impact with the ground or objectsabove the ground.

The logic controller is programmed to reliably distinguish between thenormal patterns of motion in cycling or horseback riding and those ofaccidents associated with these activities. The lower torso of the riderof a moving bicycle, motorcycle or animal normally travels through spaceas a functional conjugate of the vehicle or animal. Relatively slightvariations are caused by bouncing or by standing upon the pedals or inthe stirrups. The motion of the rider's lower torso closely mirrors theanterior-posterior orientation, acceleration, velocity andthree-dimensional trajectory of the central frame of the vehicle ortorso of the animal while the vehicle or animal is in motion. This istrue even if the animal and rider are jumping together over hurdles orthe motorcycle rider is driving at high speed around curves or overbumpy terrain. The upper torso of the rider may tilt forward, laterallyor even backward, either to reduce aerodynamic drag or to balance theforces placed on it by the motions of the vehicle. Despite this, thelower end of the torso maintains a predictable, close relationship withthe vehicle or animal. The gluteal area of the rider need not be inactual contact with the seat or saddle for this relationship to exist.The parameters governing this relationship can be programmed into alogic controller. Certain types of deviations detected while a cycle oranimal is in motion can be recognized as falls.

The motions of the cycle or horse and of the lower torso of the ridercan be independently tracked using inertial, orientation sensors. Acomparison of these motions can be made by the programmed logiccontroller. Two or more sensors or multiple, individual, uni-axialaccelerometers, gyroscopes and magnetometers may be used. The sensorsmay be separated from each other in such a way as to be mounted orembedded in a belt, collar or other wearable article that follows bodycontours in three dimensions. The individual sensor elements can belinked electrically so that they constitute a multifunction,three-dimensional, orientation sensor.

At least one orientation sensor is placed on the torso of the rider ator near the midline, preferably at the level of the lower lumbar spine.This sensor will reflect the attitude, orientation, acceleration,velocity, rotation and three-dimensional trajectory of the torso of therider. The sensor is capable of transmitting its data to a logiccontroller. Other sensors may be placed elsewhere on the torso. A secondsensor can be placed in or on the frame or seat of the bicycle ormotorcycle or on the torso or saddle of a horse. This sensor is used totrack the attitude, orientation, acceleration, velocity, andthree-dimensional trajectory of the center of the bicycle, motorcycle orhorse. This sensor is capable of transmitting data to a logiccontroller. The torso of the rider and the frame of the motorcycle orbicycle or the torso of the horse will each be represented as a simplegeometric solid. Orientation sensors placed on the torso of the riderand the frame of the bicycle or torso of the animal independentlycharacterize the orientation, attitude, trajectory and acceleration ofeach. Much of the motion pattern involved with mounting a cycle or ahorse is stereotypical, for example, it is a common human behavior that,after straddling the cycle or horse, the rider will center the buttockson the seat so that pressure is comfortably distributed on the glutealarea. This stereotypical centering maneuver can be used to establish themidline relationship of the sensor on the body of the rider with that onthe vehicle or animal.

Information from the sensors is transmitted to the logic controller,which is programmed to compare the observed attitude andthree-dimensional trajectories of the rider with that of the vehicle oranimal. A rule-based logic program defines the allowable degree ofvariation between the acceleration, orientation and trajectory of therider and those of the vehicle or animal. The logic controller isprogrammed to recognize and compare the independent, three-dimensionalmotions of the rider and those of the vehicle or animal. Divergence ofthe velocities, orientations, accelerations, rotations orthree-dimensional trajectories of the rider and the vehicle beyondprogrammed limits will be recognized by the logic controller as evolvingfalls.

Beyond the detection of incipient ejection of the rider from the vehicleby recognizing dis-conjugation between the motions of the rider andthose of the cycle or horse, the logic controller is programmed torecognize orientations, attitudes, rotational accelerations,trajectories, oscillations or other motions of the vehicle that areinconsistent with normal, controlled driving. The pitch, roll and yaw ofthe cycle or animal, together with the rate of change in these variableswill be continuously monitored by the logic circuit. Abnormal attitude,orientation or trajectory, combined with acceleration of the abnormalityof the attitude of the cycle or animal beyond programmed limits willalso be recognized as evolving accidents. This recognition can be madeeven if the sensors on the rider indicate no significant disconjugationbetween the motions of the cycle or animal and those of the rider. Whena detection of abnormal motion or attitude is made, the logic controllerwill send out a signal to deploy protective measures. Some examples ofdetection of abnormal motion or attitude are as follows: A horse rearsand falls backward, sideways and downward. The rider's torso movesdownward with unacceptable acceleration; a Motorcycle traveling at highspeed shows abrupt side to side oscillation and abrupt changes inheading, indicating an attempt of the rider to gain control; Yaw angleof the motorcycle passes 45° and shows no slowing or/and acceleration inthe rate of yaw; extreme yaw the motorcycle is succeeded by a lateralimpact

The system may include sensors that determine the distance between themotorcycle, and fixed objects in the environment or an imaging programto determine where the edges of the fixed object are. Data from thesensors can indicate the distance from objects and the rate of closure.This information can be used in conjunction with data regarding thevelocity of the motorcycle, its orientation and its heading. The logiccontroller can be programmed to recognize combinations of motorcyclespeed, heading, attitude, proximity to an object and rate of closureupon that object that would exceed the possibilities of avoiding animpact by evasive maneuvers or braking to deploy the protectivemeasures.

Riders do not just fall off motorcycles or horses. They are ejected as aresult of radical changes in the acceleration, attitude or trajectory ofthe cycle or horse. Falls and ejections thus occur in the context ofviolent motions of the cycle or animal, most typically, an abruptdeceleration. The circumstances surrounding a fall or ejection are verydifferent therefore from the relative absence of motion of the cycle oranimal during normal dismounting. It is a rule that will be programmedinto the logic circuit that the disconjugate motions, characteristic ofdismounting are permissible only when the vehicle or animal has beengradually decelerated to a velocity less than 2 miles an hour.

The motions of a rider associated with dismounting from a bicycle,motorcycle or horse represent stereotypical patterns. They areaccomplished with far lower acceleration than falls and are carried outwith predictable patterns of torso attitude, direction, rotation, andtrajectory. Algorithmic logic for dismounting is integrated into theprogram run by the logic controller. For example, normal dismountingfrom a horse would encompass the following rules: 1.) The animal is atrest, that is, is traveling less than 2 miles/hour in any direction; 2.)No pitching, rolling or yawing of the torso of the animal behind 5° isoccurring; 3.) torso of the rider is generally upright and tiltedforward; 4.) a slow rotation of the torso of the rider, covering 90 to120° is observed; 5.) a downward acceleration of the, vertical torso ofthe rider with an acceleration of less than 1 g for less than 4 feet isobserved. The logic controller is programmed to distinguish these normalbehaviors from the motions of the rider and the cycle or animalassociated with falls or ejections.

A person mounting a motorcycle, bicycle or horse also exhibits highlystereotypical behaviors. Patterns of torso motion associated withmounting a motorcycle or horse are the most important. Those forbeginning a ride on a bicycle are slightly different. While the writerof a motorcycle or force will mount, while the machine or animal isessentially at rest, a bicyclist may stand on the pedal and push thebike forward to some slight forward velocity before swinging a leg overand sitting.

As another example of normal disconjugate movement, racing bicyclistsoften stand up on the pedals and oscillate the bicycle back and forthunderneath them during the violent exertion of sprinting. However, evenduring this radical effort, predictable patterns of velocity,orientation, attitude and three-dimensional trajectory will existbetween the lower torso of the rider and the frame of the bicycle. Theyare generally traveling within a framework of similar orientation, inthe same direction and at the same forward speed. The logic controllercan be programmed to recognize even these complicated normal motionpatterns and yet recognize the degrees of disconjugation or excessivetilting of both the bicycle and rider that indicate a fall.

In contrast, when a rider falls off, or is ejected from, the cycle oranimal, a rapid, radical disconjugation of the three-dimensionaltrajectories of the rider's torso and that of the vehicle or animal willoccur. The disconjugation of the orientation, attitude and trajectorieswill be of a greater degree and will last longer than normaldisconjugate movement. This disconjugate movement would occur in thecontext of violent changes in acceleration of the cycle or animal. Forexample, radical rolling pitching or yawing of the animal is observed.Abrupt deceleration is observed. The rider accelerating with anteriorlypitched and yawing attitude from the animal. A rule-based logiccontroller can be programmed to recognize the patterns immediately.

Some additional examples include the following:

The cycle or horse might abruptly decelerate while the rider continuesaccelerating forward or laterally. Within a few milliseconds, thedisconjugate movement would be recognizable as abnormal.

In the case of an impact of a car against the side of a bicycle ormotorcycle, an abrupt, high-energy, lateral acceleration spike might bedetected by sensors on both the rider and the cycle, followed bydisconjugate movements or an abnormally rapid yawing motion of the boththe cycle and rider.

A rider being thrown from a rearing horse would show unusual upward andbackward pitching acceleration, initially in concert with the motion ofthe torso of the animal. This concerted motion would then be followed bya disconjugate motion if the rider falls toward the ground. Even themotions of the lower torso of a cowboy on a bucking bronco or bull wouldclosely follow those of the animal until he is thrown. These motionpatterns would be easily recognized by a programmed logic circuitreceiving input from orientation sensors on the rider and animal.

Certain types of motorcycle accidents, especially sliding out, in whichthe motorcyclist deliberately or unavoidably brings the side of thevehicle into contact with the ground to avoid a collision, will notinitially be characterized by disconjugate motion between the rider andthe bike. Nonetheless, characteristic motion signatures having to dowith extreme lateral tilt, lateral impact, unexpected trajectories androtations of both the rider and the cycle would allow this type ofaccident to be recognized early in its evolution by a logic circuit.

Typically, accidental falls represent 1 standard deviation departuresfrom normal descent of the center of mass of torso, attitude,trajectory, acceleration/rate, velocity, duration of free fall,acceleration/rate of torso roll and acceleration/rate of torso yaw.Failure to rise after a fall can be another programmed element forcompleted fall detection. When the look-back function of the programmedlogic controller has recognized a descent of the center of mass along anabnormal trajectory, at an excessively rapid vertical acceleration/rate,roll acceleration/rate and yaw acceleration/rate, followed by an impactgreater than 1 standard deviation above the impact force observed in thetraining phase during a normal stand-to-it transition, a presumptivefall is assumed to have occurred. If the torso attitude following thisfall is greater than 45 degrees off vertical, a completed fall will beconfirmed by the logic controller. Thereafter, failure of the monitoredsubject to show upward acceleration of a forward-pitched torso within aprescribed period of time will be interpreted as a completed fall withfailure to rise.

The actuable gas valve 20 is motor operated, or opened by melting,moving, or dissolution of a plug. The melting, moving, or dissolution ofthe plug can be accomplished using electrical energy delivered from thepower supply 24 and controlled by the logic controller 22 and deliveredto the actuable gas valve 20 by the electrical bus 26. The valve 20 canbe a ball valve, erodeable membrane, needle valve, gate valve, or anyother suitable valve that can be fully or partially opened at high speedwhen activation occurs.

FIG. 4 illustrates a front view of a person 44 wearing the APG shorts10. The APG shorts 10 are deflated in this illustration. The APG shorts10 further comprise a plurality of separate inflatable chambers 12, oneor more accelerometers 14, one or more gyroscopes 16, a high pressure orcompressed gas source 18, an actuable gas valve 20, a logic controller22, a power supply 24, an electrical bus 26 and one or morenon-inflatable regions 46. The APG shorts 10 cover the pelvis, hips andupper femur of the person 44. The non-inflatable region 46 shown in FIG.4 is in the area of the crotch where high-speed inflation could causedamage to genital organs. A falling person would not normally needprotection at the front of the garment in the crotch area because thisis an area, which would not receive any impact from the most probabletypes of fall.

FIG. 5A illustrates a side view of a person wearing the APG shorts 10.The person 44 is standing in this illustration. Outer clothing is notshown but could be worn over the APG shorts 10.

FIG. 5B illustrates a side view of a person 44 wearing a pair of APGshorts 10. The person 44 in this illustration has slipped from astanding position and is in the process of falling. The APG shorts 10have detected that an unusually high rotation rate is occurring and thatgravitational acceleration has suddenly diminished more than in half. Asa result of this information, the APG shorts 10 are in the process ofinflating.

FIG. 5C illustrates a side view of a person 44 wearing a pair of APGshorts 10. The person has completely fallen and has landed on the groundwith the greatest impact being absorbed by the buttocks and hip area.The APG shorts 10 are fully inflated to their operational pressure. Theinflated APG shorts 10 prevent direct impact between the person's 44 hipor pelvis and the ground. A fractured pelvis is avoided in thiscircumstance. The entire fall takes place in approximately 0.25 seconds.

FIG. 6 illustrates a pair of APG shorts 10 comprising a plurality oftotally isolated or separated inflatable compartments 60, a plurality ofsources of high pressure or compressed gas 18, a plurality of actuablegas valves 20, a plurality of gas vents 64, a system electrical bus 26,a system electrical output bus 62, a logic controller 22, a power supply24, an inner fabric layer 34, an outer fabric layer 36, one or moreaccelerometers 14, one or more optional gyroscopes 16. The separateinflatable compartments 60 may be comprised of the inner gas impermeablefabric layer 34, the outer gas impermeable fabric layer 36 and aplurality of gas impermeable seals 38.

Referring to FIG. 6 and FIG. 1, the inflatable compartments 60, in FIG.6, differ from the inflatable compartments 12 of FIG. 1 in that they aretotally isolated and do not have the manifolds 28 or other passagewaysleading from the compressed gas source 60 to the compartment 60. Thereaction time of the device shown in FIG. 6 is much quicker than that ofthe device of FIG. 1 in that the gas does not have to travel throughtubes or passageways to reach a remote chamber 12. Instead, the gas isvented directly into the chamber 60. A plurality of airbag inflators arerequired, one for each gas source 18. The triggering energy for theairbag inflators is routed through the electrical output bus 62. Thelogic controller 22, the power supply 24, the accelerometers 14, thegyroscopes 16 and the rest of the system bus 26 are as described as inFIG. 1.

Alternatively, the device as illustrated in FIG. 6 may have a highpressure or compressed gas source 18 that is a solid or liquid materialthat is catalytically or pyrotechnically made to undergo a reaction,such as oxidation, that releases the correct amount of gas into thecompartment 60 required to develop the specified pressure. Suchpyrotechnic or catalytic devices have the property of being much smallerand lighter than a compressed gas canister and would not be visible,protrusive, or obtrusive.

The plurality of isolated chambers 60 are especially advantageous for alarge APG garment such as a coat or trousers. It is not as necessary fora small garment such as a collar or a pair of shorts. It is stilladvantageous, for reasons of bulk and accelerated activation times, touse distributed inflation systems as described in FIG. 6 in smallgarments.

FIG. 7A illustrates an active protective garment in the configuration ofan APG collar 70. The APG collar 70 is permanently affixed or integralto a standard jacket, coat, or vest, or the APG collar can be removablyaffixed to the jacket, coat, or vest. The APG collar 70, shown in FIG.7A, is in its deflated, unactivated state. Referring to FIGS. 1A and 7A,the APG collar 70 comprises all the components of the APG shorts 10 butis specifically configured to protect the neck and at least part of thehead of the person 44 wearing the APG collar 70. While the APG collar 70may only need one inflatable chamber or compartment 12, it may have aplurality of such chambers 12 to improve pressure distributionthroughout the APG collar 70 once activated.

FIG. 7B illustrates the APG collar 70 following activation. The APGcollar 70 has activated because the person 44 wearing the APG collar 70has begun to fall. Rotational and acceleration sensors in the APG collar70 have determined that a fall is in progress and the logic controllerhas sent a signal to open the valve to the compressed gas canister sothat the compartments 12 fill to the pre-determined pressure. The APGcollar 70 has expanded upward to protect the back of the head, the sideof the head, and the neck from impact. In addition, the APG collar 70provides stiffness to the neck and head to minimize the risk of cervicalspinal injuries by preventing torsional stress to the upper spine. TheAPG collar 70 expands upward under the chin and, in conjunction with therear and side head supports, keep the neck straight and aligned duringan impact.

The face may be protected by a compartment 12 of the APG collar 70 thatexpands upward at the front of the head. Alternatively, in the APGcollar 70, a compartment may be formed inward over the top of the headto provide protection to the top of the head.

A compartment of the APG collar 70 may extend downward along the spineto provide protection and stiffening to the spine during an impact, thusreducing the chance of or extent of spinal injury.

Such an APG collar 70 is a useful adjunct for persons riding bicycles ormotorcycles or a person engaging in sports such as skiing,skateboarding, water skiing, snowboarding, and the like. Oftenparticipants in these activities prefer not to wear head protectionbecause of style or comfort reasons and the APG collar 70 will stillprovide these people with impact protection. For these sportingapplications, internal pressures and times to activation may need todiffer from those when simply falling. Reaction times may need to be onthe order of an air bag in a car. Sophisticated algorithms will berequired in the logic controller to distinguish between a crash eventand normal occurrences during some of these activities.

FIG. 8A illustrates a deflated APG jacket 80 being worn by an individual44. The APG jacket 80 is normal in appearance and can be styled to matchany trend or garment design. This APG jacket 80 does not furthercomprise an APG collar 70 as described in FIGS. 7A and 7B but such anAPG collar 70 may be comprised by the APG jacket 80. Referring to FIGS.1A and 8A, the APG jacket comprises all components specified for the APGshorts 10 of FIG. 1A. Referring to FIGS. 7B and 8B, the operationalparameters for the APG jacket 80 are more similar to those for the APGcollar 70 than the APG shorts 10 because of high speeds and occasionallow gravity events that might be encountered during the activitiesspecified for the APG collar 70.

FIG. 8B illustrates the APG jacket 80 following activation on a person44 who is falling. The APG jacket 80 has a plurality of compartments 12that have inflated and will continue to inflate to the specifiedpressure prior to the person 44 hitting the ground. The APG jacket 80further comprises arm compartments 82 that have also inflated to protectthe wearer 44 from arm impact and potential broken bones.

The APG jacket 80 may be configured as a shirt or undershirt that iscompletely hidden under outer layers of clothing.

FIG. 9A illustrates a pair of APG pants 90 being worn by a standingindividual 44. Referring to FIGS. 9A and 1A, the APG pants 90 compriseall the elements or components of the APG shorts 10. A greater number ofchambers 12 are required for the APG pants 90.

FIG. 9B illustrates the pair of APG pants 90 following activation on aperson 44 who is falling. The APG pants 90 have a plurality ofcompartments 12 that have inflated and will continue to inflate to thespecified pressure prior to the person 44 hitting the ground. The APGpants 90 may further comprise a compartment 12 that expands upward fromthe waist to protect the back and abdomen of the person 44. Such backand abdominal protection protects from impacts and also from torsionalstresses that could cause strained back or abdominal muscles orligaments. The control componentry of the APG pants 90 is affixed to thebelt area of the APG pants 90 to maximize mobility, although one or moremotion sensors may be placed further down the leg.

The APG pants 90 may be configured as underpants or an undergarment thatis worn completely hidden beneath outer layers of clothing.

The material of the garment may be fabricated from fibers that arehighly flexible in their unactivated state. Following activation, thesefibers become more rigid and provide additional impact, penetration, andskid protection. Such materials are especially useful for motorcycle andbicycle riders that become abraded from falling. Nitinol fibers may beincorporated into the weave of the fabric of the APG garment. Whenactivated, the nitinol is electrically or resistively heated to cause aphase transformation from a martensitic to an austenitic state. Thenitinol fibers shorten to tighten up the weave or they pull the weave ata bias to cause the weave to become stiffer. Ohmic or electricalresistive heating of nitinol requires very little time and the responsetime is less than 1/100 second.

The nitinol may also be used to cause the fabric to become quilted or tootherwise thicken so as to provide additional padding for the wearer.The nitinol used to quilt the fabric could be interspersed withinstandard fibers of materials such as, but not limited to, polyester,polyimide, polypropylene, PTFE, or the like and would bulk or bunch upthe fibers to form the quilt. Such a system would be reuseable and wouldnot require replacement of protective elements, in contrast to usingairbags, of which at least the igniters may, most likely, need to bereplaced following activation.

The nitinol shape-memory elements may be comprised of nanofabricated ormicromachined into the cloth of the garment. Activation of themicroscopic nitinol shape-memory elements by applying electricity to theelements, causes them to change shape to stiffen the fabric or cloth ofthe garment.

Fibers may be extended to project outward from the outer surface of theAPG garment. The fibers, like hairs, serve the purpose of creating aslip layer and minimizing shear on the surface of the fabric, thusminimizing abrasion and tears that potentially can damage the personwearing the APG garment. Such fibers may be used in a helmet to enhancehead protection. The fibers may be permanently affixed to the helmet orhat or they may be selectively retractable or extendable based ondetermination of a dangerous condition by a logic controller. Materialssuitable for such fibers include, but are not limited to, steel,polyester, polytetrafluoroethylene (PTFE), polyolefin, Kevlar, and thelike. The fibers are a suitable enhancement for the protection affordedby the APG collar 70, the APG pants 90, or the APG coat 80. The fiberlength ranges from 0.1 inches to 3.0 inches and preferably from 0.25inches to 1.0 inches. The fiber density is preferably sufficient tovisually obscure more than 50% of the surface of the APG garment.

The fibers or hairs on the garment may advantageously be affixed to alayer of material that is separated from the main surface of the garmentor helmet. The layer itself may be of low friction material such asPTFE, FEP, or the like, or it may be lubricated in the space between thelayer supporting the fibers and the main surface of the garment orhelmet using materials such as PTFE, silicone oil, or the like. Relativemotion of the fiber-supporting layer is beneficial in deflectingglancing forces directed at the APG or helmet. The fibers or hairsthemselves also serve to deflect glancing blows to the garment.

In FIG. 10, a pair of APG shorts 10 are shown in rear view. The APGshorts 10 further comprise a plurality of pockets 100, a plurality offasteners 102, a plurality of fastener holes 104, a base garment 106, aplurality of removable isolated APG chambers 108, and a plurality ofbreathable regions 110.

Referring to FIGS. 3 and 10, the removable isolated APG chambers 108further comprise one or more accelerometers 14, and/or one or moregyroscopes 16 or rotational accelerometers. The removable isolated APGchambers 108 further comprise a power supply 24, a logic controller 22,a high pressure or compressed gas source 18 and an actuable valve 20 orairbag inflator. The actuable valve 20 or airbag inflator and theaccelerometers 14 or gyroscopes 16 are preferably hard wiredelectrically to the logic controller 22. All components are preferablyaffixed to the interior surface of the removable isolated APG chambers108. The logic controller 22 further comprises wireless communicationsubsystems for short-range communication with other removable isolatedAPG chambers 108 removably affixed to the base garment 106 by beinginserted into the pockets 100, which are integral to the base garment,and secured in place by fasteners 102 and fastener holes 104.

Referring to FIGS. 3 and 10, the wireless communication between thelogic controllers 22 on each of the APG chambers 108 is made by methodsincluding, but not limited to, microwave, infrared, ultrasonic, radiowaves or similar. The transmissions are preferably digitally encoded tominimize the risk of interference from outside sources. The logiccontrollers 22 preferably comprise fail-safe mechanisms to activate uponimpact but primarily activate upon determination of a fall in progressas evidenced by accelerometer or gyroscope data.

The APG shorts 10 illustrated in FIG. 10 are beneficial because theisolated APG chambers 108 are removable and the base garment 106 iswashable. The number of breathable regions 110 is maximized in thisconfiguration to enhance comfort and wearability of the APG shorts 10.

The fasteners 102 and fastener holes 104 comprised in the base garment106 are illustrative of typical fasteners. Other fasteners suitable forthis application include but are not limited to, Velcro, snaps, zippers,and the like.

The APG may comprise three each three-dimensional accelerometers. Theseaccelerometers each read in the X, Y, and Z axis. The three-dimensionalaccelerometers are located one at the base of the neck, one at or nearthe right iliac crest and one at or near the left iliac crest. The iliaccrest defines a specific location at or about the hip area. The threeaccelerometers feed nine channels of acceleration data into the onboardlogic controller or computer through digital input or analog to digitalconverters. The logic controller or computer calculates a derivative ofthe signals over time, specifically by integrating over time, to providevelocity, and takes the integral of the velocity data over time toprovide distance. The acceleration, velocity, and distance data areconstantly evaluated by a rule-based system that determines whether themeasured parameters are within the range of normal safe human motion orwhether a fall in progress is occurring and thus triggering activationof a protective device.

The APG can further comprise an optional sonar, proximity, or positionsensor to detect proximity to objects and for calibration of theaccelerometers. This type of sensor is capable of detection of injuriousfalls by combining proximity detection (the distance from an object) andclosing velocity detection (speed at which an object is beingapproached). Such a sensor utilizes basic sonar techniques by emitting aset of ultrasonic pulses whose echo is used to perform bothmeasurements. The basic device consists of an ultrasonic transmitter (ortransmitters) and a corresponding ultrasonic receiver (or receivers).The basic principle of operation is for the transmitter to periodicallyemit a set of ultrasonic pulses, which will bounce off of any nearbysolid object. These pulses bounce off of nearby solid objects and returnto be detected by the receiver. Distance is determined by the time takenfor the audio return signal. Velocity is determined by the change inreturn time (corresponding to a change in distance) between differentpulse groups (corresponding to a change in time).

The ultrasonic transmitter should operate in the range between 40 KHzand 70 KHz. This frequency range is roughly the middle of the range usedby Bats and is sufficiently above the human hearing range to avoid anynegative sensations. High frequency is also more effective at closerange measurements and does not propagate as effectively throughbarriers such as doors and walls (a desirable characteristic).

Simple distance measurement is possible. The velocity of sound isroughly 700 miles per hour or 1027 feet per second. This results insound traveling 1 foot in approximately 0.97 milliseconds. For a roundtrip reflection off of a hard surface from a 2-foot distance would be3.9 milliseconds while from 1 foot would be 1.95 milliseconds. This iswell within the range of almost any microprocessor or digital signalprocessor on the market today.

The approach velocity of concern for falls is in the range of 4 milesper hour or 5.9 feet per second. The final foot of an injurious fallwould take approximately 0.17 seconds. There is sufficient time for morethan 40 complete echo pulses to be transmitted and received during thisperiod of time. Velocity is calculated by determining the differencebetween the echo time (distance measurement) of one echo group and thenext. For example if echo pulses are emitted at 0.1 seconds apart andthe closing distance to an object is 4 miles per hour, the change in theecho time is more than 1 millisecond for each pulse (See Table 1 for thecomplete closing sequence). Again this is very practical set of timesand calculations to perform for any microprocessor or digital signalprocessor.

TABLE 1 Echo Times for the last second of a 4.0 MPH approach velocityTime Distance Echo (sec) (feet) (ms) 1 5.87 11.43 0.9 5.28 10.29 0.84.69 9.14 0.7 4.11 8.00 0.6 3.52 6.86 0.5 2.93 5.71 0.4 2.35 4.57 0.31.76 3.43 0.2 1.17 2.29 0.1 0.59 1.14

The time between echo pulse groups can be varied based on distance. Whenthe distance is great, the pulses can be far apart to conserve energy.As the distance gets closer, the echo pulse group rate can be increasedto provide increased accuracy for both distance and velocity. Thisapproach is useful in conserving battery power or system energy.

A single frequency/single pulse technique would be very simple but ishighly subject to interference. The transmitted ultrasonic signal shouldbe a combination of several short pulses at detectably differentfrequencies. This technique will prevent any single interference sourcefrom disabling the detector. A second significant type of potentialinterference is objects directly adjacent (such as sitting in a chair,leaning against a wall, etc.). Sonar techniques have a characteristicblind spot preventing the detection of objects very close to thetransmitter/receiver. The existence of this characteristic blind spotprevents directly adjacent objects from creating any interference.

The potential for false positives (trigging a pending impact conditionat excessive velocity) must be carefully evaluated. Concern has beenexpressed about the potential of a false trigger when a person walkspast a solid object (but does not impact the object). In general if theapproach velocity is below the identified injurious velocity, then nopotential for a false trigger exists. Efficiency of the sensor isincreased when it is determined if normal daily activity createsvelocities, which exceed the critical injurious velocity. Initial reviewof material indicates that there is indeed a gap between normal dailyactivity velocities and an injurious velocity especially for people inthe age and activity group to which these detection devices would apply.Nevertheless, the concept of utilizing multiple dissimilar sensors ofwhich the proximity/velocity sensor is part of a system, which willprovide a high degree of reliability while minimizing the potential forbeing a nuisance to the user.

The digital signal processor, logic controller or computer may comprisesoftware and hardware that allows for a training mode. In this mode, theAPG is worn by the patient and the patient goes through a series ofdefined or undefined movements representing normal daily movement forthat individual. This information is used to define parameters of therule-based system or neural net software that monitors the APG sensorsand determines whether or not to activate protective mechanisms. Thetraining mode is generally enabled by a caregiver by generating inputcode to the computer or by activating a switch which starts trainingmode. Training mode is activated and deactivated by a manual switch butsuch switching can be either automatic, timed, or software-driven.

The training mode comprises three basic requirements. First, themanufacturer of the APG predetermines a set of 3 dimensionaltrajectories and acceleration profiles and programs those into the APG.These acceleration profiles represent several common composite 3dimensional motions that can be classified by acceleration, velocity,rotation, distance or sequence as a falling condition for a majority ofpeople. By way of example, the manufacturer may preset a set ofacceleration profiles defining, for example, a) slipping or; b) trippingforward. The APG is then sold or leased to a user, containing the presetprofiles for categorical fall motions. The user can then elect to inputhis, or her, own particular or individual set of acceleration profiles.The user identifies to the APG that the input activities define “normal”or “routine” activities for the particular user. They are “normal” or“routine” for the user in that they do not represent activities wherethe user is actually falling. If any of these user set profiles coincidewith any of the manufacturer-preset profiles for categorical falls, theuser removes the preset activity as a condition for deployment of thegas source. As a result, the user can engage in any routine activity,e.g. vigorous calisthenics, without danger of deployment of the APG.

The sensors can be calibrated with respect to a pre-assigned baseline.This calibration is either done with the aforementioned training mode,or by use of other transducers or external reference points. A patientmay be fitted with the APG and a caregiver uses external instrumentationto measure the exact locations of the sensors or implants that guidelocation of the sensors. A sonar or position device may be used todetermine the position of each transducer (accelerometer, other positionsensor, rotational sensors, etc.) or certain reference points on thepatient.

The APG system may provide a self-test function to ensure that allsystems are within normal operating parameters. This self-test can bemanually activated, automatically activated, or activated on a timedbasis, once a day, for example. The APG system, further comprises on-offswitching to disable the system as desired. This on-off function can beset so that only a caregiver can operate it or it can be set that thepatient can also operate the on-off function.

In order to reduce the number of false positives, the logic controllermay be programmed with predetermined rules that define the motionsignatures for the major activity states as well as the transitionsbetween those states. Other rules define the significant departures fromthe normal motions that indicate falls.

The accelerometers or sensors may be taped to the body, implantedsubcutaneously or intramuscularly or mounted on a specially designedgarment. Power is transmitted to the sensors transcutaneously throughcoils or through RF ID type systems with antennas distributed within atleast a portion of the active protective garment. The computer and powersupply are external and part of the garment. Implanted orsurface-mounted devices serve as positioning clips or locating devicesto ensure placement of the sensors at the correct location on the body.Such implanted devices may comprise magnets, or, or electronicallycommunicating RF ID device. Surface-mounted markings include tattoos,scars, and the like.

The motion sensors, consisting of the gyroscopes, magnetometers, gravitysensors and accelerometers, linear or rotational but especially linear,are, in a preferred embodiment, separated by distance sufficient togenerate relative motions. The accelerometers should be spaced togenerate data from different parts of the body, particularly the upperand lower torso. The spacing of the accelerometers may be one on theleft iliac crest, one on the right iliac crest, and one at or near thebase of the neck. Other configurations are also appropriate, so long asthe sensors are placed at some distance apart from each other so thatthey are able to discriminate the rotational data readings from eachmotion sensor. For example other regions at or about the hip may besuitable as substitutes for the iliac crest. Three eachthree-dimensional accelerometers spaced in this configuration cantranslate in three axes at their locations as well as rotation about allthree major axes. The accelerometers can be placed on a part of the bodywhere the relative positions remain relatively constant so thatrotational accelerations, rotational velocities and distances can becalculated with minimal errors caused by changes in spacing. The sensorlocation is optimized so that conjugate and disconjugate motions of thebody can be distinguished.

The system may comprise one or more algorithms, implemented throughsoftware, firmware, or hardware. An exemplary algorithm for a typicalslipping fall backward will trigger activation of the device if thefollowing conditions are met:

-   -   1. Both hip accelerometers receive initially little downward        acceleration (normal status);    -   2. The neck accelerometer accelerates posteriorly in the        anterior-posterior plane of the patient while the hip        accelerometers accelerate, simultaneously with the neck        accelerometer, anteriorly or not at all;    -   3. The hip accelerometers begin accelerating toward the ground        or in a direction toward the feet with some posterior component        with composite vertical velocities (calculated by taking a        derivative function of acceleration over time, specifically by        integration) reaching greater than 1 meter per second;    -   4. The neck accelerometer continues to measure accelerations in        the posterior direction with integrated overall velocities        exceeding 1 meter per second;    -   5. The activation of the triggering mechanism for the airbag        will preferably occur once velocities exceed 1 meter per second,        although other abnormal motion sequences may trigger deployment        of protective measures at velocities well below this threshold.    -   6. As aggregate or composite velocities approach 2 meters per        second, an impact is imminent.

Another exemplary categorical fall algorithm for a typical tripping fallforward is:

-   -   1. both hip accelerometers receive initially little downward        acceleration (normal status);    -   2. the base of neck accelerometer suddenly accelerates        anteriorly in the anterior-posterior plane of the wearer while        the hip accelerometers accelerate, simultaneously with the neck        accelerometer, only slightly anteriorly or not at all;    -   3. the neck accelerometer continues to accelerate and reaches        the derivative integrated velocities in excess of 1 meter per        second at which point triggering of the protection device is        activated;    -   4. the pelvic accelerometers provide similar anterior        acceleration measurements indicative of high velocity, anterior        and downward rotation and imminent fall.

As another example, should composite velocities exceeding negative 1meter per second occur without the relative rotation of the neckrelative to the hips, activation of the protection mechanism would notbe warranted. Such a condition could occur only in a car or other movingvehicle, jumping off a substantial height, etc.

The APG shorts 10 may include a GPS system and a transmitter suitablefor communications with cell phone systems to notify other people oremergency people that a fall has occurred and the APG shorts wereactivated. Inter-APG signals may be transmitted via wires or by wirelessmethods. The Active Protective Garment may be a coat, pants, shirt,vest, helmet, or other type of clothing. The system may be designed toprotect the wearer from a fall from standing, from bed, from beingthrown off a motorcycle or bicycle, or it may protect the wearer fromfalling a substantial distance such as 10 to 30 feet.

The system may include one more multifunction motion sensor arrays anddata fusion algorithms in the motion sensors or control system. Thesensors may comprise three axis accelerometers, inertial measurementunits and gyroscopes, angular velocity sensors, magnetic field sensorsand gravitational sensors. The control system can recognize composite,sequential, three-dimensional movements. Preferably, two multifunctionmotion sensor arrays would be used in the APG system. Sampling rates forthe entire system will generally fall in the range of 10 to 100,000samples per second and preferably between 100 and 10,000 samples persecond. Suitable sensors include Model MT9 inertial measurement unitsavailable from Xsens.

A magnetometer (compass type device), gyroscope (inertial measurementunit), or gravity sensor (level type device) are beneficial in makingthe necessary measurements. A magnetometer can update its position usingtoday's technology at a rate of around 100 samples per second, whichwould be sufficient for use on the APG. The magnetometer is the idealway to calibrate the system's orientation relative to, say, magneticnorth, etc. It could also serve as the primary measurement device formotions such as pelvic rotation.

The programming of the logic circuitry to remember and subsequentlyrecognize the sequences of three dimensional motions of the upper andlower torso that characterize normal walking, sitting down, assumingrecumbency, rising from the sitting position, stooping to pick up anobject and other activities of daily living is a beneficial feature ofthe system. The activities of daily living and the motions of accidentalfalls can be recognized and reliably distinguished from each other bythe integrated outputs of two or more multifunction motion sensorslocated on the human torso. In this construction, the torso may berepresented as a box or other geometric solid that may further betracked through space and time. In an embodiment, the box or geometricsolid representing the torso may comprise flexing elements to simulatebending of the spine. The actions of the upper and lower portions of thegeometric solid, representing the torso, may tracked independently tofollow flexion or extension. The separate sensors are important intracking the motion of the two portions of the torso, previouslydiscussed. This plurality of sensors is important in discrimination of afall in progress from a motion of daily living such as stooping over topick up an object from the floor. The reduction of the torso to ageometric solid is beneficial in simplifying the model for analysis bycomputational means.

The logic circuitry is advantageously programmed with rules thatdistinguish normal motions from fall-associated motions by the observedaccelerations, velocities, directions, rotations and distances of motionof the upper and lower torso sensors and by the actual sequence in whichcomposite motions occur. The operative rules will be derived fromobserved normal activities of the individual and stereotypical humanbehaviors such as the act of sitting down. Other rules will refer to thehallmarks of categorical fall motions based on accelerations,velocities, directions of motion, rotations and distances or sequencesof motion that do not occur during normal activities and that indicatethe loss of balance and the presence of an accidental fall. An exampleof such a rule includes the rapid posterior or postero-lateral anddownward movement of the upper thorax as the pelvis moves downward. Sucha combination of motions represents a categorical fall.

An alternative version of the system can, perform frequent, automaticre-calibration of the height of the sensors above the ground by rulesreferring to the particular activity in which the monitored subject isengaged. For example, when the logic circuit recognizes the motions ofstanding up or walking, it can be automatically and continuouslyrecalibrated to know that the pelvis-level sensor is at a height abovethe ground that was measured and programmed into the logic circuit, withthe subject standing, at the time the sensor is first worn or implanted.The thoracic sensor can also be known by the logic circuit to bevertically above the pelvic sensor by a measured and previouslyprogrammed or inputted distance. The logic circuitry is able torecalibrate the position and orientation of two or more of the motionsensors on or in the torso relative to various landmarks. Theselandmarks include: the height of each sensor above the ground or floor,the spatial relationship of each sensor with respect to the othersensors, the relationship of each sensor to the earth's gravitationalforce, the relationship of each sensor to the earths magnetic field, andthe relationship of each sensor to the anterior-posterior axis of thebody by reference to rules based on observed body motions. Distancerecalibration can be accomplished using sonar or distance measuringdevices, gravitation orientation can be made using gravity sensors orother gravity measuring devices such as levels, and magnetic fieldorientation can be determined using magnetometers. The system cancomprise low-pressure airbags that expand to less than twice atmosphericpressure when fully deployed. Airbags so configured can assume thedesired shape upon inflation without becoming hard or unyielding onimpact with a surface or object. The airbags do not necessarily need tobe fabricated from fluid or gas impermeable membranes. Airbags that arefabricated from porous materials may inflate under rapid pressurizationby the airbag inflator and then deflate once their function of impactprotection or force redistribution is completed. The airbags mayadvantageously be molded or contoured and curve around the body surface,according to their molded shape when deployed. These airbags tend toform three-dimensional geometries that vary from standard flat planargeometries. The airbags may further be contoured to fit specific sitessuch as, but not limited to, the head, neck, torso, hips and pelvis. Forexample, an airbag configured for the cervical spine can be about twoinches thick upon inflation and around three to four inches in verticaldimension. The configuration is circular or substantiallycircumferential. Non-circumferential head airbags can project 10 to 12inches upward from the base of the neck so that the top of the airbagexpands above the level of the crown of the head. The airbags may alsobe advantageously sized for different individuals. The airbags may, inthis embodiment, be either custom sized or a range of predeterminedsizes, for example, small, medium, and large, may be provided. Separateairbags can be provided for the neck, head torso, and hips.

The user sensors may also be recalibrated based on the activity orposition of the user's body, without reference to any external standard.New programs can be triggered within the logic controller based upon thestate of the monitored user or on the observation of a transitionbetween states. Observed torso motions can be referenced to the bodystate or transition as being normal or abnormal. Parameters areprogrammed for allowable motions in each direction for each body stateand transition. This is performed either by a neutral network or astatistical program of pattern matching. The range of normaltrajectories during each of the transitions is established. Downwardmotions of the torso not corresponding to programmed parameters for agiven transition because of an abnormal sequence, acceleration ortrajectory are recognized as falls. The delineation of the normal motionsignatures for the standing/walking state, the seated state and therecumbent state for the transitions between states is programmed duringa training phase.

The airbags may deploy by projecting from soft, breathable, protectivepods located on or in the collar, vertical straps, struts, belts orharness, for example. The hip pods would open fully at the bottom, likea clamshell opening, to permit egress of the inflating airbag, incontrast to a holster, for example, which is functionally closed at thebottom. Pods configured for holding hip airbags would, in an embodiment,advantageously not be attached to the hip or thigh by a strap, orgarment, in contrast to the configuration of a holster. The pods, in anembodiment, may open distally and laterally to allow access for changingairbag assemblies and to permit egress for airbags being deployed fromthe pods. The pods may have soft, molded plastic hoops at their edges tokeep their shape and maintain their position on the body. The pods canbe constructed so that the packaged airbag assembly can only be insertedcorrectly. Orientation of the airbag relative to the pod is maintainedby labeling, geometries that only line up one way, providing orientationmarkers or features, and the like. Velcro strips can be provided on theairbag package and within pods, preferably color-coded, for both thesize and intended anatomic location of the airbag. For example, a greencolor might indicate the left hip, large bag. A blue airbag would bedesignated for the head. Red would designate a right rib airbag of smallsize, etc.

FIG. 11A shows a harness 200, which facilitates integration of theentire system. The harness 200 is useful for protection of the head,cervical spine, the ribs and the hips of elderly fall victims. Theharness 200 comprises a vertical spinal support 202, a plurality ofsensor arrays 204, a plurality of airbags or pods for holding airbags206, an attachment device (not shown), logic circuitry (not shown), andthe power supply (not shown). The vertical spinal support comprises astay secured to the garment such that it is vertically oriented relativeto the patient, and extends from the lower torso or pelvic brim to theupper torso or neck of the patient when the garment is worn. The harness200 could ideally be a stand-alone garment to be layered under orbetween other garments or basic harness elements could be built into avest, shirt, coat, skirt, dress, nightgown, or other clothing item. Theharness 200 appears as an open vest that is separated at the front andcan be closed at the front using attachment devices such as, but notlimited to, a zipper, button, grips, Velcro, etc. Molded plastic hoopscan maintain relative position of the aforementioned pods and theharness. The pods 206 may reversibly attach to the harness using hookand loop fasteners, snaps, buttons, or the like. The structure of theharness is such that the vertical spinal support 202 can flex but notforeshorten or lengthen so that distance between sensors 204 issubstantially fixed. Airbags or pods 206 containing airbags are located,for example, at the hips, in the middle of the back for rib protection,and in a Nehru-type collar for neck, cervical spine, and headprotection.

FIGS. 11B and 11C illustrates the harness 200 showing the verticalspinal support 202, a collar pod 206, a rib pod 206, and two hip pods206, front plackets 208, and the waist strap 210. The device may beembodied in an open harness as shown, or a full shirt or vest, with thestiff, fixed length vertical spinal support secured to the vest. Thesensors 204 could be sited anywhere along the vest or harness 200, butthe preferred location for the sensors is in or near the midline of theupper thorax and the pelvic brim. The logic circuitry and power supplycan be located anywhere on the structure of the harness 200, but mostlikely at or near the waistband of the harness. The harness may be usedto support airbags and/or airbag pods a various vulnerable areas of thebody, as shown in FIG. 12, which illustrates airbags 206 covering thelateral hip area, the lower rigs, the neck and head, and the elbow.

The sensors may communicate wirelessly, using means described elsewherein this disclosure, with the logic circuitry or the communication busmay be hard wired within straps of the harness. Alternatively, thecommunication may use a combination of hard-wired and wirelessmethodology. The logic circuitry can communicate with the gas generator,whether pyrotechnic or a gas canister and valve, using wireless or wiredtechnology. Airbags for rib, cervical vertebrae, or other protectiondevice can deploy from pods or straps on the harness. Alternatively, arib airbag assembly may be attached to the patient or the harnessdirectly by straps. The vertical posterior or anterior strut of theharness containing two or more motion sensors would have one sensor atthe level of the upper thorax and one at the level of the pelvic brim,at about the level of the fifth lumbar vertebra. In another embodiment,the system comprises a sensor array in which multiple data-fused outputsare transmitted to the logic circuitry by wired or wireless connectionmeans. A posterior or anterior strut of the body harness can beconfigured to maintain the vertical alignment of two sensors andmaintains a fixed inter-sensor distance. Maintaining a fixedinter-sensor distance is important to minimizing errors in the dataalgorithms. The harness can further comprise a vertical posterior strutcontaining closed or open cell foam or other padding elements in whichsensors, gas generators, batteries, and electronics may be embedded inthe foam for concealment and protection. The harness would preferably beoffered in various sizes to accommodate persons of different height,proportion, and body mass. The harness may further be adjustable to fita variety of size persons over all or part of the range of human shapesand sizes. The harness can further have a hook and loop, such as Velcro,or other attachment points for pods, deflated airbags, gas generators,electronics, and other system components. The belt and straps of aharness system may comprise elastic materials to maintain the harnesscomfortably close to the body and to facilitate donning and removal ofthe APG. The structure of the harness will further be water resistantand resistant to stains by way of chemical treatments to the fibersusing chemicals such as ScotchGuard, etc.

The pods may advantageously have a hook and loop fastener such asVelcro, allowing easy and quick attachment of vacuum-packed airbagassemblies with similar strips on their surface allowing for securefastening to the pod. The pods may further be fabricated from breathablefabrics such, but not limited to, as Gore Tex, cotton, loose weaves ofpolyester, and the like.

The airbags can be configured to curve upon deployment. This isaccomplished mainly by their molded shape but is assisted by theresistance provided by the inner surfaces of any common garments wornover the plane of the deploying airbag. By this arrangement, it ispossible to protect the hips and pelvis, whether the hip is flexed orextended during a fall, despite the absence of any fixed attachment ofpod to the surface of the thigh or hip. One exemplary way of fabricatinga curving airbag is to provide a segmented and sequentially expandedstructure. Each segment inflates and forms the basis of the nextsegment. Using such a segmented or curved airbag, an anatomical bodypart such as the head, neck, or hip might be completely surrounded by anairbag that deploys from a pod that otherwise does not surround the bodypart. In another embodiment, separate airbags are separately andsequentially activated, the deployment of which is controlled by thelogic circuitry to determine and control the timing, force, and speed ofinflation of each airbag. The airbags may further comprise integralhoops or other structural elements, such as sail-type battens, tofacilitate achievement of ideal shape during deployment. The airbags maycomprise reinforcing bars or struts integrated into the outer surfacefabric. The bars may be fabricated from thin pieces of high strengthmaterials such as, but not limited to, polyester, polyimide, and thelike.

Another feature of the system is to seal the airbag, along with itstriggering mechanism, inflator, or both, within a vacuum pack tominimize the size of the structure. In this embodiment, the use of talcor other material to prevent sticking of the airbag surfaces to eachother is beneficial. To further minimize the bulk of the system, the gascanisters or pyrotechnic airbag inflators may be flattened orcontour-shaped to minimize the thickness of the airbag-generatorassembly and increase wearability of the device. The airbags, batteries,gas generator, etc. may be packaged, together or separately, in ahermetically or otherwise sealed container, which is waterproof andresistant to contamination from the environment. The airbag ispreferably vacuum-packed in such a way that the vacuum pack can easilyburst or open upon deployment of the airbag.

With regard to detecting and monitoring the motion of the torso, oneembodiment is to place sensors in or on the torso, at least one sensorabove and at least one sensor below the level of the umbilicus at ornear the mid-line of the torso. In this configuration, the system canmonitor the motion of the torso as two separate units comprising anupper and a lower part. The logic circuitry can be programmed to alwaysknow where the anterior surface of the body is located, the anteriorsurface being defined as the plane generally including the abdomen andchest of the wearer.

The logic circuit is capable of distinguishing, by integration of datafrom two or more torso sensors with data-fusion algorithms, informationsuch as: the motion of walking with a gait that is normal or abnormalfor the individual, the composite three-dimensional sequence of motionsfor sitting down, the composite three dimensional motion pattern forassuming recumbency, and the composite three dimensional motion patternfor standing up from sitting. The logic circuit can further determinethe composite three dimensional motion pattern for getting into a car,the composite three dimensional pattern for ascending or descending onestep or a flight of steps, and the composite three dimensional motionpattern for picking up an object from the floor. The system can alsodistinguish categorical fall motions by evaluation of torso velocity,acceleration, direction, time, distance, rotation, sensor distance abovethe floor, sequence of motions, as well as by reference topre-programmed rules that describe categorical fall motion. The logiccircuitry can be governed by rules that are based on stereotypical humanbehavior. An example of a normal human motion is that the posteriordescent of the pelvis, will be preceded by a slow rotation of the torsoand by anterior and downward motion of the upper thorax if a patient issitting but not falling. An example of a rule describing fall motion isthat the upper thorax will never move rapidly posterior orposterio-laterally and downward while the pelvis is moving downwardunless the subject is falling.

The motion sensors can be externally powered by wired bus, RF-ID, etc.,or they can be internally powered by batteries, capacitors, or the like.The motion sensors can further comprise minor or major components of thelogic circuitry. By providing the motion sensors with some or all of thelogic circuitry, it is possible to add redundancy and the benefits ofdistributed processing to the system.

The logic circuitry is capable of triggering an audible orskin-vibrating signal to the wearer, for example a vibrator mounted inthe soles of one or more shoes, of the device if an abnormal gait isrecognized by the logic circuit. The logic circuitry is capable oftriggering a call to emergency medical services (EMS) if a fall isobserved and the patient fails to fulfill the algorithm for rising to astanding or sitting position, or if the wearer fails to activate an OKsignal on the system.

In yet another embodiment, the logic circuitry is capable of triggeringdeployment of protective devices separately mounted on the floor, astairwell, a walker, cane, wheelchair, furniture, and the like. Suchtriggering can be accomplished using wireless technologies such asultrasound, or some part of the electromagnetic spectrum. A walker canbe configured to comprise airbags to cushion the fall of a user should afall be detected on the part of the user or the walker by means ofwalker-mounted sensors. The walker can further be configured with agyroscopic device to help maintain vertical stability in the event thatan attempt is made to pull the walker over. The gyroscope can be used asa sensor or as a primary force-leveling device.

The collar of the APG can deploy airbags to protect the neck, thecervical spine, and the head. This can be done using an inner airbagthat is approximately between two and 8 inches high and preferablybetween 3 and 5 inches high. This airbag can inflate to protect thecervical spine by providing a support collar against torsion loads andto prevent compression stresses on the neck because the head and chinare supported against the shoulders of the wearer. An outer airbag orset of airbags protects the head and serves to reinforce the innerairbag. These outer airbags can also be fabricated as part of the innerairbag so that separate airbags are not used. The airbags are preferablysized and shaped to serve the intended function. By sequentiallyinflating a series of airbags, it is possible to generatethree-dimensional geometries more easily and for a full helmet to deploythat no only protects the side of the head but also the top of the head.

Most common rib fractures in the elderly involve ribs number seven eightand nine. It is important to protect these ribs as they are not wellprotected by the scapula, breast or arm. An airbag designed for the ribscan be attached by Velcro or other attachment in or on a shirt orundershirt, or built into a pod or a harness. The Velcro strip or otherfastener pre-attached to a garment would provide for ease of positioningat the correct location.

In another embodiment, the system can use sensors and logic circuitrythat recognize fall patterns and decide what part of the person, forexample the head, will strike an object and require protection. Thesystem can deploy airbags selectively to protect only those body partsrequiring protection, thus minimizing the need to replace or rechargeunnecessarily deployed airbags.

It is a desirable feature of the present invention that themicroprocessor will “know” the relative position of the thoracic andpelvic sensors. These relative positions may be known by reference to anexternal reference point, but preferably, the microprocessor willre-calibrate the vertical relationship of the thoracic and pelvicsensors each time the patient assumes a sitting position or shows themotion of walking. Under these two circumstances, the microprocessorwill be re-calibrated to recognize the position of the upper thoracicsensor as being vertically straight above the pelvic sensor at adistance programmed at the time of sensor placement or implantation.

Thus, while the preferred embodiments of the devices and methods havebeen described in reference to the environment in which they weredeveloped, they are merely illustrative of the principles of theinventions. Other embodiments and configurations may be devised withoutdeparting from the spirit of the inventions and the scope of theappended claims.

1-31. (canceled)
 32. A motion analysis system comprising: at least onefirst orientation sensor configured to detect three-dimensional torsomotion over time, the at least one orientation sensor comprising: amultiaxial accelerometer configured to detect acceleration in at leastthree orthogonal directions, and a gyroscope; at least one secondorientation sensor configured to detect three-dimensional motion of avehicle frame or an animal torso; and a controller configured to receivedata from the at least one first orientation sensor and the at least onesecond orientation sensor, the controller being programmed to processthe data to: compare the three-dimensional torso motion detected by theat least one first orientation sensor to the three-dimensional motiondetected by the at least one second orientation sensor over a period oftime, identify the degree of variation over time between thethree-dimensional torso motion detected by the at least one firstorientation sensor and the three-dimensional motion detected by the atleast one second orientation sensor, and determine whether the degree ofvariation over time between the three-dimensional torso motion detectedby the at least one first orientation sensor and the three-dimensionalmotion detected by the at least one second orientation sensor is withinan allowable degree of variation.
 33. The motion analysis system ofclaim 32, wherein the controller is further configured to process thedata to: identify parameters for the motion of the vehicle frame oranimal torso, and determine the allowable degree of variation based onthe parameters for the motion of the vehicle frame or animal torso. 34.The motion analysis system of claim 32, wherein the at least one firstorientation sensor is further configured to detect pitch, roll, and yawof the torso.
 35. The motion analysis system of claim 32, wherein the atleast one first orientation sensor is further configured to detect anacceleration of each of pitch, roll, and yaw of the torso.
 36. Themotion analysis system of claim 32, wherein the at least one firstorientation sensor is further configured to detect a velocity of each ofpitch, roll, and yaw of the torso.
 37. The motion analysis system ofclaim 32, wherein the at least one first orientation sensor is furtherconfigured to detect a total acceleration of the torso.
 38. The motionanalysis system of claim 32, wherein the at least one first orientationsensor is further configured to detect a trajectory of the torsoreferenced to gravity.
 39. The motion analysis system of claim 32,wherein the at least one first orientation sensor comprises an inertialmeasurement unit.
 40. The motion analysis system of claim 32, whereinthe at least one first orientation sensor further comprises a magneticfield sensor.
 41. The motion analysis system of claim 32, wherein the atleast one second orientation sensor comprises a multiaxialaccelerometer, a gyroscope, and a magnetic field sensor.
 42. The motionanalysis system of claim 32, wherein the at least one second orientationsensor is further configured to detect an acceleration of each of pitch,roll, and yaw of the vehicle frame or animal torso.
 43. The motionanalysis system of claim 32, wherein the at least one second orientationsensor is further configured to detect a velocity of each of pitch,roll, and yaw of the vehicle frame or animal torso.
 44. The motionanalysis system of claim 32, wherein the at least one second orientationsensor is further configured to detect a total acceleration of thevehicle frame or animal torso.
 45. The motion analysis system of claim32, wherein the at least one second orientation sensor is furtherconfigured to detect a trajectory of the vehicle frame or animal torso.46. The motion analysis system of claim 32, wherein the at least onesecond orientation sensor comprises an inertial measurement unit. 47.The motion analysis system of claim 32, wherein the at least one secondorientation sensor comprises at least one of a triaxial accelerometer, agyroscope, and a magnetic field sensor.
 48. The motion analysis systemof claim 32, wherein at least one of the first orientation sensor andthe second orientation sensor is configured for wireless communicationwith the controller.